Conservative candidates and officials in more than a dozen constituencies will not face criminal charges over inaccurately reporting their election expenses, prosecutors said.
The announcement sparked an angry backlash from Tory MPs, who threatened to campaign for the elections watchdog to be abolished, while opposition parties called for electoral laws to be toughened.
The Crown Prosecution Service (CPS) in England and Wales had been considering files from 15 police forces in relation to Conservative campaigning in the 2015 general election.
Allegations centred on why a Conservative battle bus that carried party activists to battleground constituencies was reported to the Electoral Commission as national, rather than local spending.
Parties must respect strict spending limits in each constituency, with campaigning that promotes an individual candidate counting towards local limits.
Opposition parties claimed that the snap election on 8 June was called to pre-empt criminal charges that could have seen election results voided and cost the Conservatives their narrow parliamentary majority.
Last month First Minister Nicola Sturgeon suggested the Tories may have “bought” their 2015 election victory, and claimed Prime Minister Theresa May had decided to go to the polls “before possible criminal prosecutions for alleged expenses fraud at the last election catches up with her”.
SNP MP Pete Wishart challenged the Prime Minister during PMQs in March, claiming the allegations were “at best woeful negligence, and at worst pure electoral fraud”.
Yesterday senior Tories hit back, with Conservative Party chairman Patrick McLoughlin saying the allegations were “politically motivated” and a waste of police time. He said that “false and malicious” claims were still be circulated online and warned accusers that they could be guilty of an election offence and defamation if they were repeated during the campaign.
In a statement, the CPS head of special crime Nick Vamos said: “We reviewed the files in accordance with the Code for Crown Prosecutors and have concluded the tests in the Code are not met and no criminal charges have been authorised.”
One file from Kent Police, which relates to the South Thanet constituency where the Conservative Craig Mackinlay defeated then-Ukip leader Nigel Farage, was only recently submitted and remains under consideration. The CPS has until the start of June to decide whether to bring charges in relation to expense returns there.
Mr Vamos said: “Although there is evidence to suggest the returns may have been inaccurate, there is insufficient evidence to prove to the criminal standard that any candidate or agent was dishonest.”
He added: “It is clear agents were told by Conservative Party headquarters that the costs were part of the national campaign and it would not be possible to prove any agent acted knowingly or dishonestly. Therefore we have concluded it is not in the public interest to charge anyone referred to us with this offence.”
The Conservative Party was fined a record £70,000 by the Electoral Commission for “numerous failures” in reporting its expenses for the 2015 general election, and three by-elections in 2014.
Labour and the Liberal Democrats were also fined £20,000 each last year following investigations into their 2015 General Election expenses.
Conservative candidates who were under investigation rounded on the Electoral Commission, with Karl McCartney, the incumbent in Lincoln, saying the organisation was “wholly unfit for purpose”.
Mr McCartney said Tory MPs would campaign to have the organisation abolished after the election.
Mr Wishart insisted the Conservatives were not “off the hook” and said SNP MPs would push for “tougher rules and higher standards”. He said: “Today’s CPS decision that there is insufficient evidence of criminal intent to the standard required for a prosecution is far from a clean bill of health for the Tory party.”
Labour leader Jeremy Corbyn said: “Our election laws must be enforced and must be adhered to.
“There are strict spending limits for a reason, so that money can’t buy power.”