Northerners who lent their votes to the Conservatives at the election will only back the party again if they see "serious" regeneration in their region, according to Ann Widdecombe.
The Brexit Party MEP claimed the north of England had been "forgotten about" during the election campaign, and called on Boris Johnson to do more for voters outside of London.
"It was the Brexit Party who led the way in the general election by saying early on we would cancel HS2 and put the money into northern regeneration," Ms Widdecombe told talkRADIO.
"Boris has a golden opportunity. If he can keep those votes then he has brought about a huge seachange in British politics."
She continued: "He has to produce results. No good talking. You need to see some quite serious northern regeneration. Having said that, you also have to be realistic about what you can and can't do, and focus on what you can do."
Her comments come after the Prime Minister pledged to shift a number of civil servants out of London this year, in an effort to spread opportunity and wealth across the country.
But Ms Widdecombe, a former Conservative, said the plan would not work as long as the government was based in the capital.
"You want to be very careful about gesture politics. It's one thing to concentrate on regenerating the north, it's quite another to say well, we'll send a few civil servants up there and they will get experience of living there," she added.
"It doesn't actually work if the heart of government is in London where you need your senior civil servants. It doesn't work."
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