A police force has launched an investigation into an allegation of electoral fraud relating to the 2015 general election amid claims the Conservative Party may have breached spending rules.

Gloucestershire Police would not be drawn on which constituency or consistencies the allegation may refer to or even which party but confirmed on Thursday it is probing an allegation it has received.

The investigation comes after the Electoral Commission met with police and prosecutors yesterday in a bid to ensure they do not run out of time to launch possible criminal investigations into Conservative funding of the 2015 general election campaign.

The Commission believes its ongoing probe into alleged breaches of reporting obligations will take at least another month - taking it past the one-year time limit for launching criminal proceedings.

"We have received an allegation of electoral fraud and an investigation has been launched,” a Gloucestershire Police spokeswoman said.

She added: "We are considering an application for extension on time to investigate…This is in relation to the 2015 general election."

A spokesperson for the Liberal Democrats added: “Throughout all of this we have said local campaigns should look at their returns and our central team is available to offer case by case support.

"In some areas the public have already made complaints to the police.

“Our view is that money should not be able to buy elections. It should be a battle of ideas, and not who has the biggest chequebook.”

Earlier on Thursday ministers were urged to address the allegations relating to the party's election spending. SNP frontbench spokesman Pete Wishart raised the issue during the business statement in the House of Commons.

He said: "We need an urgent statement on what's going on with the investigation of the Conservative Party for breaking campaign spending rules in last year's general election.

"The claims are absolutely extraordinary and centre around Conservative candidates, 28 Conservative candidates, failing to register the use of a battle bus for local campaigning and something like £38,000 of accommodation for local campaigns.

"If anybody's found guilty of such a charge it could result in one year imprisonment and an unlimited fine.

"Surely we must now hear what the Government's view on this is and there must be no whiff or suggestion that this Government cheated its way to power."

Commons Leader Chris Grayling said "it is for proper authorities to address issues whenever they arise".