Theresa Villiers has hit out at ULEZ on the day the emissions charge is expanded to London's outer boroughs, claiming it will “cause real hardship”.

The Conservative MP for Chipping Barnet said that ULEZ was “the wrong scheme at the wrong time”.

It comes after most Londoners became subject to the £12.50 charge earlier today (August 29).

Previously only those driving their cars inside the North and South Circular ring roads were liable to pay the charges if they had a non-compliant vehicle.

London Mayor Sadiq Khan has said that ULEZ expansion is necessary to reduce air pollution across the capital.

But Ms Villiers has now claimed that the charges will not have the desired effect, branding them “taxes”.

She said: “Expanding Ulez will not tackle air quality problems. It will also cause real hardship for people with non-compliant cars or vans.

“Imposing these new charges at a time when my constituents in Barnet are struggling with the cost of living is completely wrong.

“These new taxes from the Labour Mayor will also hit small businesses who rely on vans.

“Ulez expansion will make it harder for our local high streets to attract customers.

“And it will mean our public services find it even more difficult to recruit workers from outside London who depend on their cars to get to work. The care sector could be especially hard hit by this problem.”

Ms Villiers promised to continue opposing the expansion and urged voters to back Susan Hall, the Conservative candidate for London Mayor who has pledged to scrap the Ulez expansion, at next year's election.

Speaking today on BBC Breakfast, Sadiq Khan said clean air is “a right, not a privilege”.

He added: “We now have a really effective policy to reduce air pollution.

“It’s shown to be effective in central London and inner London, but I think clean air is a right not a privilege.

“What about outer London? Why shouldn’t they breathe clean air?

“Why should they carry on dying prematurely in numbers that could be reversed?”

To comply with ULEZ standards, petrol cars must generally have been first registered after 2005, while most diesel cars registered after September 2015 are also exempt from the charge.

Electric cars and cars which are more than 40 years old are exempt from ULEZ charges.

TfL says nine out of 10 cars seen driving in outer London on an average day are compliant.