Ukip's Douglas Carswell became its first elected MP after winning the Clacton by-election last week, securing a majority of over 12,000 votes in a decisive victory over the Tories, his former party.
Ukip is hoping to capitalise on this momentum to win the next by-election in Rochester and Strood, prompted by the defection of Tory MP Mark Reckless. But history shows that the Tories have quickly snatched back some seats they have lost in by-elections at the following national elections.
Election expert Lewis Baston told the Huffington Post UK: "It's not very unusual for the government party to regain such losses, particularly if it is winning the election nationally."
Baston, a senior research fellow at the Democratic Audit research group, stressed that Carswell was likely to survive as he had won by an "exceptionally large" margin and built up a personal vote.
But with speculation rife about how many extra MPs Ukip could get before the 2015 general election, here are five seats the Tories snatched back just months after their own by-election losses.
Clacton: 5 By-Elections That The Tories Swiftly Recovered
Birmingham Northfield(01 of05)
Open Image ModalJohn Spellar won the seat for Labour in a 1982 by-election, but his time was ended as the Tories snatched it back the following year as they also topped the polls nationwide. He later returned in 1992 to parliament as MP for Warley in the West Midlands. (credit:Matthew Fearn/PA Archive)
Fulham(02 of05)
Open Image ModalNick Raynsford won the seat for Labour in a 1986 by-election, but his time in Parliament was brought to a swift end as the Tories snatched Fulham back the following year. He later returned to parliament, representing another part of London - Greenwich. (credit:PA)
Ryedale(03 of05)
Open Image ModalMonmouth(04 of05)
Open Image ModalHuw Edwards won the Welsh constituency of Monmouth in the 1991 by-election, however he lost it to the Tories in 1992 at the general election. He did manage to claw it back at the 1997 election, being re-elected in 2001, but lost it once more in 2005. (credit:Barry Batchelor/PA Archive)
And Ribble Valley(05 of05)
Open Image ModalMichael Carr took the Lancashire seat for the Social Democratic Party in 1991, but his victory was short-lived as the Tories took it back in 1992 as they also topped the national polls. (credit:BBC)