Douglas Carswell defected from the Tories to the UK Independence Party before calling a by-election in 2014.
His re-election gave a major boost to UKIP, putting pressure on former Prime Minister David Cameron to hold the referendum on the UK’s membership of the EU in 2016.
The UK has now made an agreement on trade and other issues with the EU, just one week before the transition period comes to an end.
The deal means there will be no extra charges on goods, but UK nationals will need a visa for stays of longer than 90 days in the EU in a 180-day period.