SENIOR Labour Party figure Alistair Darling has called for a full internal investigation into allegations of vote-rigging within the local Falkirk party.

The former Chancellor said the results of the probe should be published to ensure grassroots members could see "justice is done".

The MP spoke out after witnesses in an earlier, abandoned inquiry denied they had changed their story.

Labour dropped the initial investigation on the grounds key witnesses had withdrawn their evidence. But Michael and Lorraine Kane, who claimed they had been signed up as Labour members without their consent during an attempt by Unite union activists to install a parliamentary candidate, told the BBC they had neither changed nor withdrawn their testimony.

The couple are thought to be planning to use data protection legislation to request copies of all information held on them by Labour, Unite and Ineos, where leading union activist Stevie Deans worked until recently.

Mr Darling said: "There needs to be a very thorough investigation. I understand the police are looking at matters now. If they proceed, then that is what'll happen but if they don't, there needs to be a full inquiry and I am quite clear that the results have to be published because that is the only way in which people will be satisfied that justice is done and been seen to be done."

His comments piled more pressure on Labour leader Ed Miliband to re-open the party's inquiry.

Scots Labour leader Johann Lamont had said the party "should look at" restarting the investigation but said any findings would not be published.

Grant Shapps, the Conservative Party chairman, said: "Ed Miliband has been totally silent about this ever since he caved in and cancelled Labour's inquiry. If Ed Miliband is too weak to stand up to his union paymasters, then he is too weak to stand up for hard-working people."

Mr Deans faced claims, strongly denied by Unite, that he helped sign up a number of new Labour members without their knowledge as part of a bid to seize control of the Falkirk West constituency party and install Karie Murphy, a close friend of the union's leader Len McCluskey, as parliamentary candidate for the constituency. He quit his job at the Ineos plant in Grangemouth amid claims he was using the company's time and resources for his Labour Party activities.

On Sunday, it emerged he had agreed to step down as chairman of the Falkirk West Labour party.

A Labour spokesman said Mrs Kane had been contacted by the party's top official Iain McNicol yesterday and stood by a sworn affidavit from September which formed "part of the reason" the party decided there was insufficient evidence to proceed with its initial investigation.

The spokesman added: "Therefore we have not seen any new evidence to justify further action. It is right to base our decision on a sworn affidavit confirmed again today by Mrs Kane.

"There is now a police inquiry going on into other issues around Falkirk and we will of course consider the outcome of that inquiry."

A Unite spokesman said nothing new "has emerged to contradict or undermine the finding of both the Labour Party and Police Scotland that Unite had broken neither the law nor Labour rules in Falkirk".