LONDON - British Prime Minister David Cameron faced a tough political test on Thursday as voters cast their ballots in a by-election seen as a bellwether for the state of national politics.
Voters in the town of Corby, central England, were voting for a new member of parliament to replace Louise Mensch, a high-profile member of Cameron's Conservative party.
Mensch, a "chick-lit" author whose husband Peter is the manager of US hard rock band Metallica, announced in August that she was resigning in order to move to New York and spend more time with her family.
Her seat, which she won by a slim majority in the 2010 general election, is regarded as an electoral barometer with the town returning a candidate from the winning party in every general election for the past 30 years.
Reclaiming the swing-seat would be a significant victory for the opposition Labour party, who were ousted after 13 years in power in 2010 and replaced by the coalition of Cameron's Conservatives and the centrist Liberal Democrats.
Labour are around 10 points ahead of the Conservatives in national opinion polls as the government struggles to reverse Britain's stubborn economic downturn despite the introduction of steep spending cuts aimed at reducing the deficit.
The opposition party is expected to win two other by-elections on Thursday in Manchester Central and Cardiff South, seats vacated by retiring Labour MPs.
Mensch played a leading role in parliamentary hearings over the phone-hacking scandal at Rupert Murdoch's News of the World tabloid and was seen as a potential minister.
She has published 14 novels under her maiden name Louise Bagshawe, and set up her own politically-focused social networking website, Menshn, in June.
Results for all three by-elections are expected from early Friday.