The next general secretary of the Labour party is set to be Chris Lennie, senior party officials have confirmed.

It is understood that Lennie, a former acting general secretary with current responsibility for Labour Party fundraising, will be appointed for what a party insider described as "an interim period" of two years. The relatively short-term nature of the appointment is understood to be an attempt to address concerns among the trade unions that their favoured candidates have been overlooked.

According to the source, GMB official Iain McNicol, regarded by many observers as a leading contender for the position, is unlikely to even be shortlisted. A second candidate, Joe Irvine, former T&G official and political officer to Gordon Brown, is said to be a "marginal" prospect for the shortlist.

Lennie's appointment is apparently being brokered by senior Ed Miliband staffers, who have contacted selected NEC members to drum up support for their preferred candidate.

"Ed's team have moved heavily behind Chris," said the source. "The only serious opposition was McNicol, which is why he won't be included on the shortlist."

Some party insiders claim Lennie's appointment is designed to send a signal that Labour's leader is putting distance between himself and the trade unions. However, other sources insist Lennie's fundraising experience is they key to the appointment.

"Ed's not trying to pick a fight," said the insider, "but he just doesn't want a 'political' general secretary. He needs someone who can get to grips with practical issues like the funding crisis, and the staffing problems at Victoria Street."

Lennie is regarded by Labour sources as a solid, experienced official, who carries minimal political or ideological baggage. "Chris is basically a fixture," said one MP. "He's been around for a long time, not doing anything especially remarkable, but not doing anything particularly terrible." Another party official said, "Chris is coming in with one brief and one brief only. Cut costs and sort out the finances. That's it."

One colleague believes he will be well placed to carry out that role. "Lennie is a smooth operator," he said. "He's good at getting people to show him the money." However, another party insider was more sceptical of his fundraising record. "OK, he's got Alastair Campbell's phone number, but apart from that how many big donors has he landed?" the source queried.

Lennie will replace Ray Collins, who was appointed in 2008 following the surprise withdrawal of preferred candidate David Pitt-Watson. Pitt-Watson, a city fund manager, rejected the position after he became aware he would be personally liable for the party's outstanding £18m debt.