The Northern Research Group say ministers must start delivering on promises to rebuild after the pandemic.
The prime minister must start delivering an ambitious levelling-up programme for the north of England “at pace”, according to a group of 50 Conservative MPs.
The Northern Research Group is calling for an economic strategy focused on helping communities in the North rebuild after the pandemic.
It wants special grants for deprived areas outside London.
Ministers say they are “totally committed to levelling up”.
The NRG was founded by a number of Conservatives who won so-called red wall seats from Labour at the 2019 general election and want to push the government for greater investment for northern areas.
The pandemic has renewed attention on regional disparities.
A recent study by the Northern Health Science Alliance found the North has been hit harder than the rest of England during coronavirus, “exacerbating” regional inequalities.
At the Queen’s Speech in May, ministers said they would “level-up opportunities across all parts of the United Kingdom as Britain recovers from the pandemic”.
Prime Minister Boris Johnson is also expected to deliver a speech shortly on the issue.
NRG chairman Jake Berry told the BBC: “We have been in lockdown longer than any other area of the country.
“It’s time for the government to show the North some love with a summer of levelling up.”
He said the prime minister relies for his majority in Parliament on votes in the North and there is now an opportunity to encourage investment, jobs and industry there.
He added: “Since December 2019, we have heard a lot about plans to level up the North, now is the time to show how we can deliver.
“No one in the North cares about internal governmental turf wars.
“They want real jobs, real change, and real opportunities.
“It’s time to start delivering an ambitious programme at pace if we are going to see real progress this summer.”
The group wants a recovery plan focused on infrastructure.
It is calling for automatic grants to help deprived areas outside London, the formation of a northern growth board and – as part of a plan for better transport – the abolition of road tax and fuel duty, to be replaced with a system under which revenue raised would be kept in the North.
A government spokesperson said: “We’re investing £100bn in infrastructure this year, as well as creating a new £4.8bn Levelling Up Fund, establishing free ports across the UK and a new UK infrastructure bank in Leeds to harness private investment and fund new projects.”
The spokesman said ministers will publish a Levelling Up White Paper later this year, which will set out plans to “improve livelihoods across the country as we recover from the pandemic”.