Labour faces pressure to reopen inquiry into election-rigging allegations in Scotland

The Labour Party is facing pressure to reopen an internal inquiry that cleared one of Britain’s largest trades unions of trying to “fix” the selection of a candidate to run for a Scottish House of Commons seat.

Last month, Labour tried to put the row over the Falkirk constituency selection to bed, saying that witnesses who had claimed that they had been signed up as members of the party's Falkirk branch without their knowledge had withdrawn their complaints.

Now, however, some of the witnesses have come forward to insist that they made no such withdrawal and demanded to see the internal inquiry – one that Labour has repeatedly refused to release.

The head of the Falkirk branch, Stephen Deans, is a senior Unite official, who played a key role during this month's controversy at the giant Grangemouth oil refinery where he was convenor until he stood down last week.

The allegation is that Unite attempted to fix the Falkirk race to ensure that one of its favoured candidates would replace outgoing Labour MP Eric Joyce, who will stand down in 2015.

Following weeks of saying nothing, Scottish Labour leader Johann Lamont yesterday accepted that Labour would "certainly have to look at" reopening the inquiry "because of concerns" that it "wasn't entirely complete".

Police Scotland was invited by Labour to examine events in Falkirk, but backed away quickly saying that there was not enough evidence to justify launching a full investigation.

However, it is not clear if police saw more than 1,000 emails that were gathered by Labour for its internal inquiry – although a full dossier has been handed to them in the last week or so, it has emerged.

Leading figures in Labour, such as former home secretary Jack Straw, have already insisted that the internal inquiry into Falkirk must be reopened and published, with many believing that the current attempts to fend off pressure is doomed to failure.

Equally, there are some within Labour who are deeply unhappy at the influence now being wielded – or which is purported to be wielded by Unite – which has its own campaigns team working to get favoured candidates selected to run for Labour seats.

The controversy has been a gift for the Conservatives, who are ever keen to highlight the links between Labour leader Ed Miliband and Unite – one of the unions that decided the party leadership race in his favour in 2010.