UKIP’s leadership has slammed the Tories for “putting party before country” by calling an early election, implying they are pre-empting a series of by-elections that could be called following a police investigation into alleged electoral fraud.

Mrs. May repeatedly and forcefully denied she would call a snap election after the referendum. But after passing the Article 50 Bill with a massive majority, today claimed she “reluctantly” changed her mind because the Lib Democrats, Labour, and the House of Lords were trying to disrupt Brexit.

Her U-turn also comes exactly a month after reports suggested Conservative Party figures were fearful of a series of by-elections that could be called after up to 20 of their MPs were alleged to have overspent in the 2015 campaign.

A dozen police forces have now passed files to the Crown Prosecution Service over the allegations, with prosecutors preparing to decide whether to charge the MPs or their agents after a 10-month investigation.

“…The prospect of a slew of Tory-held by-elections caused by the seeming systematic breach of electoral law at the last election, predominantly in places where UKIP were pressing the Conservatives hard” could have influenced the decision to hold an election now, suggested Paul Nuttall in a statement.

Deputy UKIP leader Peter Whittle also said the decision was “utterly cynical”, adding: “But we’re having [a general election] now and my party is actually quite excited about it.” Speaking on the BBC’s Daily Politics, he said there was “no question” the Tories were acting in their own self-interest, adding:

“The Scottish nationalist were told [by Theresa May] that it is quite wrong to try and hold an independence referendum – inappropriate during Brexit negotiations. [But] somehow it’s alright to have a general election.”

The police have not revealed which Tory MPs are under investigation, but one is thought to be Craig Mackinlay, who narrowly defeated the former UKIP leader Nigel Farage in South Thanet in 2015.

The Conservatives were fined a record £70,000 on 16 March 2016 over missing and unreported payments, with the Electorial Commission claiming the rule breaking gave them a “realistic prospect” of an unfair advantage over UKIP in the seat.

In his statement, the UKIP leader claimed another reason for the unexpected election was because the Tories were also seeking to take advantage of their lead in the polls.

“We welcome the opportunity to take UKIP’s positive message to the country,” he said. “However, we believe that the Prime Minister’s decision to call this election is a cynical decision driven more by the weakness of Corbyn’s Labour Party rather than the good of the country.”

A YouGov poll conducted earlier this week revealed the Tories are enjoying a massive 21-point lead over Labour, meaning they are likely vastly increasing their majority in Parliament.

In his interview, Mr. Whittle argued that his party could perform well in the up-and-coming election – destined to be framed around Brexit issues – despite Mrs. May echoing UKIP by promising to implement the referendum result with “no way back”.

“People are getting worried,” he said. “They hear nothing about what the government is going to do on migration. All they hear… is that migration at the current levels might go on for another 10 years.”

Mr. Nuttall added on Twitter that every vote for his party would be a reminder to the government that Britain wants a “clean” Brexit.