Ukip leader Nigel Farage is "mulling over" whether to run for Chris Huhne's Eastleigh seat, following the former minister's dramatic resignation.
The MEP for the South East of England will make a decision by the end of the week, Ukip spokesman Gawain Towler told the Huffington Post UK.
Mr Towler said: "Nigel is thinking about it. He is in Strasbourg and mulling it over but there will be a formal candidate selection process.
"The nomination must be decided by Monday next week and by that time a Ukip candidate will be selected. A candidate will probably be announced by the end of the week."
If he does decide to run, Mr Farage will be hoping to improve on the 952 votes he received when he contested the same seat in 1994.
Bookies have installed the Tories as the favourites to snatch the prized Hampshire seat.
But local Liberal Democrats are defiant about their chances of hanging on to a constituency they have controlled for 19 years.
Council leader Keith House told the Huffington Post UK: "The Tories are in total disarray in Eastleigh, they have had such an electoral battering from the Lib Dems in the past few years.
"The big thing about the Lib Dems in Eastleigh is that the team is bigger than the individual - whether that's Chris Huhne, Keith House or anyone."
No decision has been made on choosing the Lib Dem candidate, he added.
The Conservatives trailed the Lib Dems by almost 4,000 votes at the 2010 General Election, with Labour a distant third. Ukip's Ray Finch polled 1,933, a 3.6 per cent share of the vote.
Bookmaker William Hill believes Mr Huhne's resignation has handed the seat to the Tories, making them 1/2 favourites to win the by-election, with the Lib Dems 6/4 to retain it. Ukip are 33/1 shots with Labour made 100/1 outsiders.
"Mr Huhne had a majority of some 3,800 and that could be tricky for the Lib Dem candidate to defend in the current climate" said Hill’s spokesman Graham Sharpe.