The Conservatives have angrily accused the Crown Prosecution Service of trying to interfere with the result of the election by charging a Tory candidate with alleged electoral fraud less than a week before polling day.

The CPS charged Craig Mackinlay – a former MP who defeated Ukip's former leader Nigel Farage in South Thanet at the 2015 general election – with offences under the Representation of the People Act 1983.

If found guilty Mr Mackinlay faces a fine or up to a year in prison and could have to resign his seat in Parliament if he is re-elected, sparking a by-election in the Tory marginal seat.

Any court case could see Nick Timothy, the chief of staff to Theresa May, giving evidence because he played a key role in Mr Mackinlay’s 2015 campaign.

The CPS came under fire yesterday for announcing its decision just six days before June 8 election despite admitting that it could have made its charging decision by a “statutory time limit” of June 11, three days after the election.

Last month the CPS said it had considered files from 14 other police forces but had decided not to bring charges against any other Conservative MPs or officials.