Mr McNulty said people were listening to the government on 42 days
A Labour minister has mounted an attack on Conservative by-election winner David Davis comparing him to cartoon character Homer Simpson.
Tony McNulty also accused the ex-shadow home secretary of "vanity" for quitting his seat to trigger the contest.
He said Mr Davis should have made his argument on civil liberties in Parliament instead.
Mr Davis has accused Labour of "cowardice" for not fielding a candidate in Haltemprice and Howden.
Mr McNulty said Mr Davis's resignation over the government's plans to extend pre-charge detention for terror suspects to 42 days had been unnecessary.
The Home Office Minster - who helped push the 42-day measure through the Commons, against opposition from the Tories, Lib Dems and some Labour MPs, said: "It does not need David Davis to give the country permission to have a debate on the issues."
'Message getting through'
Following Prime Minister Gordon Brown's recent admission that it was "absolutely correct" to compare himself to Heathcliff, the romantic anti-hero of the novel Wuthering Heights, Mr McNulty was asked who Mr Davis reminded him of.
He replied: "David Davis? Probably Homer Simpson."
He also claimed the government's message that changes to anti-terror laws were needed to improve security was getting through.
He told the BBC: "People do listen. We have to make the argument. I have taken the argument for 42 days around the House [of Commons] and, for the last 18 months, around the country."
Mr McNulty said the Liberal Democrats had been "mugged" by Mr Davis into not putting up a candidate in Haltemprice and Howden.
'Put the case'
But Lib Dem president Simon Hughes returned the criticism, saying that Labour should have contested the seat.
He said: "Mr McNulty needs to answer the question that, if you are so sure that the question [of 42 days] is important to Britain, why did you not put the case?"
Party leader Nick Clegg added: "David Davis has done well in keeping the issue of 42 days' detention without trial in the spotlight.
"However, the challenge for his party is to stop being piecemeal protectors of liberty and realise that freedom is indivisible."
He added: "The Conservatives are a long way from being defenders of liberty. David Davis's lonely stand only highlights the big questions that still remain over whether the Conservatives really are committed to protecting our freedom."
'Fired a shot'
Mr Davis said his victory in the by-election, with a majority of 15,355, proved he had been right to quit and stand for re-election.
"We have fired a shot across the bows of Gordon Brown's arrogant, arbitrary and authoritarian government."
He told BBC Radio 4's Today programme: "The trouble with this is, from the beginning, the Westminster village hasn't really understood that someone wants to take a stand on a matter of principle that may have some effect on themselves."
He also accused Labour of "spectacular cowardice" for not fielding a candidate.
The Green Party, with 1,758 votes, came second - its best performance in a parliamentary by-election.
Principal speaker Derek Wall said: "The willingness of so many Labour and Liberal Democrat supporters to put their faith in the Greens, even though it's our first run in the constituency in recent years, shows that mainstream voters see the Greens as a real alternative to bland and complacent politics."
The English Democrats, who had campaigned against the EU treaty, were just 144 votes behind - making it a record night for them too.
The remaining 23 candidates lost their deposits.