Sir Keir Starmer is facing continued pressure from MPs and charities, as the government prepares to announce changes to the welfare system this week.

The government will outline plans to reduce spending on health benefits on Tuesday, but is facing accusations vulnerable people could lose out.

Ministers are looking at tightening criteria to qualify for Personal Independence Payments (PIP), one of the key disability benefits.

They have abandoned plans for a one-year freeze to PIP payments, after disquiet from MPs.

But there is significant unease among Labour MPs about the cuts, spreading far beyond Sir Keir’s usual internal opponents.

More than 3.6 million people currently claim PIP – which is designed to help compensate those with disabilities and long-term health conditions for higher living costs such as the purchase of a wheelchair or having to take more taxis to get around.

It had been initially reported that the government would consider not increasing PIP payments in life with inflation for a year. But that idea could be withdrawn after many usually loyal Labour MPs voiced strong opposition.

After attending a private meeting of Labour MPs last week, one MP told the BBC that freezing PIP would be “unforgivable”.

“Some people have very complex disabilities. Part of the social contract is they are supported,” they said.

Another MP, a usual supporter of the prime minister, told the BBC: “Most of us broadly agree that there are lots of people who don’t work but should, and have no problem with getting them into work.

“But punishing those who are especially vulnerable and have severe disabilities is unacceptable.”

Backbenchers have also expressed frustration at a lack of communication from ministers.

But on Monday, Treasury Minister Emma Reynolds asked Labour MPs to wait for the official announcement, adding: “some colleagues are jumping to conclusions about our plans before they’ve heard them”.

“We’ll set out further details, but the severely disabled and the most vulnerable will always get support, and there will always be a safety net,” she told BBC Radio 4’s Today programme.

The reason reform of the benefits system is being announced now is because the cuts form part of the Spring Statement on 26 March.

Initially this was expected to be a pared-back parliamentary moment with Rachel Reeves only required to formally acknowledge new economic forecasts produced by the Office for Budget Responsibility (OBR).

Over recent weeks, however, it has become clear that the OBR has told Rachel Reeves that the £9.9bn “headroom” she had at the time of her October Budget has since been wiped out by the rising cost of government borrowing – requiring savings.

This was the buffer Reeves had against meeting her own borrowing rules.

There are some Labour MPs, including ministers, who believe that instead of responding by pursuing severe spending cuts, Reeves and Sir Keir should consider changing those rules so that the government can borrow more money, or increasing tax.

On the Today programme, veteran Labour MP Diane Abbott echoed calls from others on the left of the party for additional taxation of wealth.

Reeves’ allies, though, argue that further tax or borrowing would spook the financial markets and result in the cost of borrowing going up even further.

On tax, the chancellor is constrained by commitments Labour made during the general election not to increase income tax or VAT.

The government is facing a towering disability welfare bill. Total spending on health and disability benefits is forecast to rise from £64.7bn in 2023-24 to £100.7bn in 2029-30.

The biggest contributor to this would be from welfare spending on working-age adults, according to the Office for Budget Responsibility.

PIP is the second-largest element of the working-age welfare bill, with spending on this projected to almost double to £34bn by 2029-30.

And claimant numbers, for PIP and Universal Credit payments, have increased significantly in the four years since the pandemic- about 37% over the past four years.

There are now about 4 million people getting at least one of the disability benefits – about 10% of the working age population, said Tom Waters from the Institute of Fiscal Studies.

Just under half of these claim for mental health problems, said the analyst, adding that “a majority of the increase” was from people claiming mental and behavioural problems as their main condition.

During his appearance on the BBC’s Sunday with Laura Kuenssberg programme, Health Secretary Wes Streeting was asked if he agreed with experts that warn of an overdiagnosis of mental health conditions.

The health secretary said he wanted to “follow the evidence and I agree with that point about overdiagnosis”.

“Here’s the other thing, mental wellbeing, illness, it’s a spectrum and I think definitely there’s an overdiagnosis but there’s too many people being written off,” he said.

The health secretary’s comments prompted the mental health charity Mind to warn it was important to be “extremely careful” with the language around diagnoses to avoid stigmatising people.

Streeting also said the government “wants to support people who need help the most, and we’ve got to make sure that there is a wide range of support and that everyone’s playing their part.”

Shadow Education Secretary Laura Trott accused the government of being “all over the place and divided” over welfare reform.

When asked if the Conservatives would back the welfare changes, she said her party supported the “principle of welfare reform” but “we’re not clear on the plan”.

The SNP has urged the prime minister to scrap the “cuts to disabled people”.

The party’s Westminster leader Stephen Flynn said the Labour government had “boxed itself in with its Tory austerity rules” on public spending.

Speaking to BBC Radio 4’s Westminster Hour, the chief executive of charity Citizen’s Advice said the government was “pulling the quick and easy lever” by taking “money out of the system”.

Dame Clare Moriarty also accused the government of “not having done all the work to make sure that people can actually be supported into work”.

Writing in the Times on Monday, Greater Manchester mayor Andy Burnham said he recognised the need for reform of the system, but urged “caution” on benefit changes.

He said: “It would trap too many people in poverty. And to be clear: there is no case in any scenario for cutting the support available to disabled people who are unable to work.”

Marija Taseva was enjoying a night out with her sister at the Pulse club in Kocani, North Macedonia, on Saturday when disaster struck.

They were watching DNK, a popular hip-hop duo in the country, when a fire broke out, which killed at least 59 people and injured 155 others.

“Everyone started screaming and shouting ‘get out, get out!'” the 19-year-old told Reuters.

People desperately tried to escape the flames but there was only one exit for around 500 people, as the only other door at the back of the venue was locked.

“I don’t know how but I ended up on the ground, I couldn’t get up and at that moment people started stomping on me,” Ms Taseva said.

She eventually managed to get to safety, but her sister did not.

“My sister died. I was saved and she wasn’t.”

Police have detained 15 people, with Interior Minister Pance Toskovski saying that there are “grounds for suspicion that there is bribery and corruption” linked to the fire.

Those detained include the owner of the venue and former government officials.

Prime Minister Hristijan Mickoski has said there will be “no mercy”, regardless of political rank or party affiliation.

The fire started around 02:30 local time (01:30 GMT) on Sunday when sparks from pyrotechnic devices hit the ceiling, which was made of highly flammable material, Toskovski said.

Described as an “improvised nightclub” by the local press, the venue, located in a town around 100km (60 miles) east of the capital, Skopje, did not have a legal licence to operate, Toskovski said.

It had previously been a carpet warehouse, and police are investigating.

“Most of the dead suffered injuries from the stampede that occurred in the panic while trying to exit,” the head of the Kocani hospital, Kristina Serafimovska, told reporters.

“Seventy of the patients have burns and carbon monoxide poisoning,” she said, according to AFP news agency.

Vladislav Gruev, a specialist in reconstructive and plastic surgery at the University Clinic for Surgical Diseases, has been treating survivors.

“Most of them have extensive burn injuries, above 18% surface body area, second and third degree burns on the head, neck, upper torso, and upper limbs – hands and fingers,” he said.

Inspections on Sunday showed several “abnormalities” in the venue, including “deficiencies” in the fire-extinguishing and lighting system, said public prosecutor’s office spokesman Biljana Arsovska.

Speaking outside the hospital, Red Cross volunteer Mustafa Saidov said the majority of those who died were young people.

“Inside where they are identifying the victims, the situation is far worse. You see that the parents are also quite young people, in their 40s. Their children are 18 or 20 years old.”

“The situation is brutal, chaotic, the stories are very sad, and unfortunately many young lives are lost.”

One man, whose nephew was injured in the fire, said some people have been unable to locate their children.

Many are angry and searching for answers, like Dragi Stojanov, who lost his only child in the fire.

“Let me tell you in front of everybody. Film me. I am a dead man, I lost everything… the whole of Europe should know,” he told reporters.

“After this tragedy, what do I need this life for? I don’t need it.

“I had one child and I lost him.”

North Macedonia’s President Gordana Siljanovska-Davkova said there needed to be accountability for what happened.

“None of the responsible this time should avoid the law, the justice and punishment too,” she said.

“Nothing is worthier than human life, specifically young life.”

The most seriously injured were being taken for treatment in specialist clinics in Bulgaria, Greece, Serbia and Turkey, she added.

The government has declared seven days of national mourning, and it will hold an emergency session as part of ongoing investigations into how the incident unfolded.