It was announced yesterday that the famously Eurosceptic Mr Carswell would be stepping down as a Tory MP for Clacton and standing for the seat again in a by-election.
He will represent UKIP when the poll takes place after being welcomed to the party with open arms by its charismatic leader Nigel Farage.
Tring man Mark Anderson, who will stand against David Gauke in 2015, said: “I am delighted that Douglas Carswell has joined UKIP.
“Guided by the same remorseless logic that has guided many of us to UKIP.
“He does not believe that Tory leadership are serious about a proper referendum on EU membership.
“When we vote in a general election, we expect the people we elect to actually run our country. We expect them to have our interests on top. And we expect them to act with honesty and integrity.
“For a change, Douglas Carswell seems to want the same, and he should be commended for that.
“David Gauke enjoys a healthy majority over that of his Clacton counterpart. But he does not own our votes.
“UKIP has a real vision for Britain, of putting power back into our parliament and returning responsibility back to individuals.
“We now show a credibility that is lacking in any of the other parties with policies to support the future of a global Britain. More people will learn about UKIP’s vision on the back of these events, and about myself as I look to represent you here in South West Hertfordshire.
“I am delighted Douglas Carswell has joined us, and I look forward to many voters ‘defecting’ to UKIP, I am just sorry we can’t give you all a press conference too.”
Speaking yesterday, Mr Farage said ‘many more’ Tory and Labour MPs are considering whether to defect to UKIP.
He said the number who pursue the idea will depend on how successful Mr Carswell is in the by-election.
He said: “I’ve spoken to people in the Conservative Party and the Labour Party who do not want Britain to be borderless, who think this is doing great damage to the working opportunities of people in Britain.
“I don’t think Douglas Carswell is going to be considered an isolated eccentric – there are other MPs out there considering their options.”