North Norfolk MP Norman Lamb said he was taking nothing for granted after UKIP's Douglas Carswell won the party's first parliamentary seat in Clacton.
The Liberal Democrat MP said he understood a time of economic turmoil created a lot of anxiety about the future, but said he strongly believed that UKIP did not have the answer.
'I have no doubt that the rise of UKIP will have an impact on the general election,' said Mr Lamb.
'I am totally respectful of people's reasons for feeling anxious and wanting to challenge the system.'
Mr Carswell defected from the Conservative party in August, and was re-elected under his new colours last week.
And when Mr Lamb was asked if he was worried UKIP's prospective parliamentary candidate for north Norfolk Michael Baker would have an impact on his number of votes, he said: 'All the evidence suggests the challenge is still between myself and the Conservatives but I am taking nothing for granted.'
Mr Baker however disagreed, saying the Clacton result showed voters UKIP could win seats - and he felt the fight in north Norfolk was between him and Mr Lamb, with voters disillusioned by the Tory-Lib Dem coalition.
As UKIP candidate at the 2010 election Mr Baker polled 2,680 votes (3p), and Mr Lamb 27,534 (55.5pc) running Labour (2,896) close for third spot behind the Conservatives (15,928).
Mr Baker added: 'No seat is safe. We have a real chance.'
The Conservative prospective parliamentary Ann Steward. Labour's is Denise Burke.
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