They argued that the cities need “certainty that the HS2 terminus will be at Euston” amid reports that the line linking the capital to the Midlands and the North could terminate in Ealing rather than central London to save billions of pounds. They are also pressing for an underground HS2 station at Manchester Piccadilly.
“Both in London and the North, there is a consensus that current plans for both stations could permanently damage Britain’s economic ambitions,” they said in the letter, which was also signed by the leaders of Camden and Manchester City councils Georgia Gould and Bev Craig.
It emerged earlier this year that transport leaders were weighing up whether to scrap the final leg of the rail scheme and have it terminate in Ealing.
HS2 bosses were said to be concerned that sky-high inflation and an increase in construction costs would make finishing the multi-billion-pound project unaffordable.
Options believed to be under discussion included delaying the building of the Euston terminus to 2038 or scrapping it altogether.
But London leaders on Thursday argued that the people of Camden had “already made significant sacrifices” in order for the Euston project to go ahead.
“We want to ensure HS2 connects with a London terminus at Euston, not six miles outside the city centre. Many have had their homes and businesses demolished or relocated,” they said.
“The delay in ensuring the HS2 terminus is in Euston is causing continued frustration and uncertainty for many businesses and communities.”
They added that London would need significant support to help manage capacity on the Elizabeth line if it terminated at Old Oak Common.
They said: “Without the Government supporting the acquisition of additional rolling stock for the Elizabeth line, to carry people between the temporary terminus of Old Oak Common and central London, the capacity benefits of the line could be virtually wiped out due to the delay.”
The intervention comes as the western leg of the HS2 Phase 2B Bill reaches the committee stage in the House of Commons.
Local leaders will formally make their case to the committee next month and also argue for an underground station at Manchester Piccadilly that would support Northern Powerhouse Rail.
Chancellor Jeremy Hunt earlier this year insisted he could not see “any conceivable circumstances” where HS2 would not run into Euston. But refused to comment on the timescale of the project as the costs soared.