Andy Burnham has promised to end rough sleeping in England in his first pledge as prime minister, allocating an additional £340m over three years as he seeks to replicate the homelessness schemes he rolled out in Greater Manchester.

Speaking in front of Downing Street immediately after becoming prime minister, Burnham said he would try to get people off the streets “at the earliest opportunity”.

The announcement was welcomed by homelessness campaigners, who say the pledge can be met with enough money and political will.

The prime minister’s critics, however, greeted the promise with scepticism, pointing out that despite having set out a similar goal as Greater Manchester mayor, Burnham had overseen four years of rising street homelessness.

Burnham said on Monday: “On my first day as prime minister, I’m announcing this government’s commitment to finally end long-term rough sleeping across the UK at the earliest opportunity.

“We’ll get to work immediately, bringing together national and local government with the investment needed to get it done.”

Officials said the government would now put an extra £340m into its homelessness strategy – equivalent to £113m a year – which would come from unused parts of the housing department’s budget.

They said the money would pay for 1,200 new homes and help support 3,000 people over five years.

The money comes on top of £3.5bn, the previous government’s allocation for its homelessness strategy, which ministers said at the time was designed to halve the rates of long-term rough sleeping.

Steve Reed, the housing secretary who oversaw that strategy, was sacked from his post on Monday as Burnham began the process of putting his cabinet together.

Burnham’s promise, which the former Labour leader Jeremy Corbyn had planned to announce if elected prime minister, aims to emulate the success of the “Everyone In” policy which the government briefly enacted during the Covid pandemic.

It also echoes a pledge he made when he was running for the Greater Manchester mayoralty in 2017, when he promised to eliminate rough sleeping in Manchester within three years if elected.

After he won that election, he had some early success with his homelessness policy, both with his rough sleeping programme, known as A Bed Every Night, and his broader scheme to tackle long-term homelessness, called Housing First.

In his first five years as mayor, rough sleeping dropped by two-thirds, which supporters say showed the merits of corralling different parts of government around the same aim.

Those in Manchester at the time say Burnham was able to use his position as mayor to force greater collaboration between different councils and government bodies to tackle the problem.

For example, he made the 10 councils under his jurisdiction share data so that someone who was rough sleeping in Bolton, for example, could also be tracked if they came into central Manchester during the day.

He also made sure landlords did not evict tenants because of relatively minor misdemeanours, which experts say is a major cause of street homelessness.

Shabnum Mustapha, a former official at the Greater Manchester mayoralty, said: “In the early days it was hard, trying to bring together a bunch of statutory agencies and organisations which have been working on this problem for decades and decades.

“But by taking a big tent approach, working with different councils, other parties and organisations such as faith groups, he had a lot of success.”

Critics, however, point out that in each of the past four years, rough sleeping has risen, so the level is now three-quarters of what it was in 2017.

Supporters say rates were difficult to keep down after the national government ended its pandemic support schemes. His opponents, however, accuse Burnham of having taken his focus off one of his foundational policies.

James Cleverly, the shadow housing secretary, said: “His record in Manchester showed initial success, then failure once his focus shifted. It looks like he’s taking money from local projects to fund this announcement, so lots of the country will be disappointed.”