LABOUR has suspended its selection process for the Falkirk Westminster seat held by disgraced MP Eric Joyce following concerns about "membership recruitment".

The decision comes amid allegations the Unite union recruited dozens of its members to the Labour constituency.

The party admitted "concerns had been raised" about the impact on the selection process and will now investigate the allegations before it restarts the search for a candidate.

Last week, the Unite-backed frontrunner for the candidacy of the safe seat, Karie Murphy, pulled out.

The party was forced to abandon a local consultation – paid for by Unite – on whether an all-women shortlist should be used after complaints the poll was flawed. Some members believed the move was a "stitch-up".

Ms Murphy, a former union official who runs the office of Tom Watson, Labour's election co-ordinator, made headlines in January when she said she would throw a party to mark the death of Baroness Thatcher.

Last month, Richard Bryce, local party vice-chairman, resigned from his post, citing divisions within the branch.

Eric Wilson, a senior UK party official brought in to help deal with the issue of selection, wrote to new members saying there had been "questions raised about the validity of some of these new applications".

Earlier this week, Mr Joyce, who is no longer a Labour member, wrote: "Apparently, Unite recruited 100 new members to Falkirk over a very short period."

He added: "I think it's great that so many people want to join the Labour Party. The UK party (ie, the actual Labour Party) seems unsure about it all, though."

Mr Joyce, 52, left the party last year after being fined £3000 for assaulting a Tory MP in a Commons bar. He has also said he does not intend to stand at the General Election in 2015.

A Labour spokesman said: "We have suspended the start of the selection process of the Falkirk parliamentary seat. Concerns have been raised about membership recruitment which need to be investigated. An officer of the party will carry out an investigation to ensure the integrity of the process."

A source said the party was now taking "swift and decisive action" as the selection process was due to begin on Sunday.

A Unite spokesman said the union was "fully confident that in relation to Falkirk West, as in all seats where our members are active in the Labour Party, our conduct is correct and fully compliant with the rules of the party".

Two candidates remain in the now suspended race: Gregor Poynton, UK political director for communications firm Blue State Digital; and Linda Gow, a former Falkirk Council leader.