Labour is expected to retain the Wythenshawe and Sale East seat tonight and all eyes are on which of the other parties can secure second place.
With foul weather forecast for today the ability of the parties to persuade voters to go to the polls is likely to be a major factor in the outcome.
While UKIP is often considered a threat to the Conservatives tonight’s result will be closely analysed for signs that the party is also taking support away from Labour ahead of May’s local and European elections.
The by-election was triggered by the death of former Northern Ireland Minister Paul Goggins last month.
Labour candidate Mike Kane said: “We’ve worked tirelessly for the last few weeks knocking on thousands of doors to win the trust and support of voters across my home constituency.
“Paul Goggins was a dear friend of mine and was a man much loved and admired by people of all political persuasions here.It would be an honour to follow in his footsteps, but we’re taking nothing for granted and are working hard for every vote.”