|The by-election in Oldham East was necessitated by the annulment of a former Labour minister's victory [Reuters]
Britain's Labour party has comfortably won a contest for an empty parliamentary seat in a result that reflected the Liberal Democrats' fall from favour since joining a Conservative-led government in May.
Opposition Labour's Debbie Abrahams won 14,718 votes on Friday in the marginal Oldham East and Saddleworth constituency - 3,558 more than closest rival, Lib Dem Elwyn Watkins. In May's election, Labour beat the Lib Dems to the seat by just 103 votes.
The Lib Dems have had a tough time since signing up to Britain's first coalition government since the second world war, freefalling in opinion polls and facing stern criticism for backing austerity cuts they had once passionately opposed.
While one defeat will not cripple the centre-left Lib Dems nor the coalition, it is a boost for Labour's new leader Ed Miliband and will spur critics of Nick Clegg, the deputy prime minister, whose popularity has fallen since he entered office.
Many Lib Dem voters worry that government spending cuts and tax rises are unfairly targeting the poor. Some feel betrayed by Clegg who, up until forming a coalition government, had opposed the Conservative approach of cutting the budget deficit swiftly.
The by-election in Oldham East and Saddleworth - the first ballot-box test for the coalition - was called after a Labour politician was ousted after being found guilty of smearing his Lib Dem rival in the 2010 election.
With the contest pitting the two governing parties against each other, there were reports that David Cameron, the Conservative prime minister, had scaled back his own party's campaign to help out his Lib Dem allies and take pressure off Clegg.
Kashif Ali, the Conservative candidate, secured just 4,481 votes, more than 7,000 less than his 2010 election score.
With Europe embroiled in a sovereign debt crisis, financial markets are on alert for signs of instability within Britain's coalition, as a secure government is seen as crucial to executing a plan to effectively wipe out a record budget deficit by 2015.