Boris Johnson has been urged to keep his promises after a report suggested the North is set to receive more than £2,300 less per person in transport spending than London.
The Government's planned transport spending for London is almost three times more per head than the North unless investment in the Northern Powerhouse gets the go-ahead, a think-tank said.
That figure rises to seven times more per person than in Yorkshire and the Humber or the North East, according to the IPPR North research based on Government figures and published on Monday.
Its analysis said the capital will receive £3,636 in transport spending per person, while the North will receive £1,247 in planned spending.
The study also suggested that the spending gap had widened over the last decade, with the boost in London being 2.5 times more than in the North.
IPPR researcher Luke Raikes said:
Shadow transport secretary Andy McDonald said:
Andy Burnham, the mayor of Greater Manchester, said the Government should be ''embarrassed by the growing disparity between the North and South.''
A spokeswoman said the Government ''did not recognise these misleading figures''. They went onto say: