Former Labour MP Thomas Docherty. John Stilwell PA Archive/PA Images LONDON — Labour is set to reject calls to run a big name candidate in the upcoming crucial Copeland by-election, in favour of picking a more local figure, Business Insider understands.

Sources close to the Labour campaign in Cumbria say that local councillor Gillian Troughton is the strong favourite to be selected for the by-election, which will be triggered once outgoing Labour MP Jamie Reed officially resigns.

Troughton, who won a council by-election in the area in 2015, has not responded to Business Insider's request for comment but did confirm her intentions in a private Facebook posting on December 24.

In the comment, posted in a group setup to organise Labour's campaign in Copeland, Troughton said: "Shall declare my hand at this point — I will be standing. I think I am a good candidate and won a county council by-election October 2015 under Jeremy [Corbyn] and am also a borough councillor."

She goes on to say: "Have heard several rumours (and make educated guesses) but there is at least one other strong candidate with local links (not Ed Balls) but not sure if he's indicated yet."

Business Insider understands that the "other strong candidate" Troughton mentions is likely to be former Labour MP Thomas Docherty.

The former MP for Dunfermline and West Fife was born in Copeland and worked at the nearby Sellafield nuclear plant before entering politics. He was elected in 2010 and held a number of shadow positions under Ed Miliband's leadership, including shadow deputy leader of the House, before being replaced by an SNP candidate in 2015.

Labour councillors who we spoke to when we visited Copeland last month mentioned Docherty as a name to look out for when the shortlist is announced on January 19. He put his name forward in 2005 but was defeated by Reed, who went on to hold the Cumbrian seat, which has been controlled by Labour since 1931.

Docherty would not comment about his possible candidacy when Business Insider spoke to him on Wednesday evening.

Docherty would be the most well-known name in the running to be Labour's candidate. However, local party members insist that name value isn't the most important issue. Copeland is a communal, tightly-knit area, with very local concerns such as the future of the cut-ravaged West Cumberland Hospital.

It's for this reason that Troughton may well have an advantage over Docherty, if the latter puts his name forward.

Docherty does have obvious links to west Cumbria, but Troughton has spent her entire political life representing the area, sitting on a number of local committees like the County Council Local Committee for Copeland.

As a local Labour campaigner who doesn't want to be named told Business Insider: "She's local... She has a strong handle on the big issues in the seat. I can only see them going for an out of towner if the locals put forward are genuinely hopeless. Cumbrians don't like people coming from across the country and telling them how to do things."

One person who has confirmed their intention to stand is Shropshire councillor Usman Ahmed. Speaking to the News & Star newspaper earlier this week, he said: "I know the area, the people and the issues. I know the NHS is a real issue in Copeland and as a passionate believer and supporter of the NHS I will campaign hard to protect all services."

It had been reported that Workington councillor Andrew Lawson, who was previously the country's youngest mayor when he was elected to be Workington's mayor at the age of just 21 in 2012, would be putting his name forward. However, Lawson announced on Thursday afternoon that he would not be seeking the candidacy, saying "it was not right time" for him to try and enter Westminster politics.

Applications for the candidacy close on Monday, with the candidate being chosen and announced by the constituency Labour party in two weeks time on Thursday, January 19.

The by-election will be a huge test of both Jeremy Corbyn's leadership and the party's relevance in working-class, pro-Leave seats like Copeland. Labour's majority was reduced to just over 2,500 votes at the last election, and bookmakers make the Tories odds on (51%) to win the seat from Labour (38%), according to the Smarkets betting market. Senior Labour sources told us that both Corbyn and shadow business secretary Clive Lewis are set to make the trip up to Cumbria from London in the coming weeks.

Labour campaigners in Whitehaven, Cumbria last month. Adam Payne/Business Insider

It was initially thought that the by-election will take place in February. However, if Reed officially stands down on January 31, then there must be at least 21 working days before a by-election can be held, meaning it likely won't be held until March at the very earliest. A senior Labour source told Business Insider that holding it in May is currently being considered, as it would coincide with local elections due to take place that month.

For the Conservative Party, the Copeland by-election represents a fantastic opportunity. Gaining a seat would not just be a statistical triumph, boosting the party's parliamentary majority and defying the historical rule that governments perform badly midway through their terms, but a huge symbolic victory, as it would mean taking from the Labour Party in a seat it has held easily for decades.

Speculation regarding who will stand for the Tories has so far been more muted. Stephen Haraldsen, who was defeated by Reed at the last general election, is being touted as a likely candidate. "He has a real chance if they [the Conservative Party] put more money behind him," one councillor told us when we visited Copeland month.

Chris Whiteside is another possibility. The former chairman of the Cumbrian Conservatives is a former parliamentary candidate and also stood in the Copeland mayoral election in 2015.