DERBY North MP Chris Williamson says he believes that, if a referendum on UK membership of the EU takes place, people who fail to vote should be fined £50.
He spoke as a bill calling for a referendum in 2017 on the country's membership was approved by the House of Commons yesterday.
The legislation got through despite some media claiming Lib Dem and Labour MPs were trying to delay its passage.
It will now move to the House of Lords for scrutiny early next year.
Mr Williamson spoke for 28 minutes as he called for members of the electorate who did not vote to be fined £50.
His speech prompted Commons Deputy Speaker Eleanor Laing to tell him to hurry up.
Mr Williamson said: "£50 is sufficiently high enough to create an incentive and to concentrate people's minds.
"If it were any less than that, they might not bother to vote.
"If it were higher than that, it would be unreasonable. I must say I did pluck the figure out of the sky, but I thought that £50 was reasonable."
Martin Horwood, Liberal Democrat MP for Cheltenham, was critical of Mr Williamson's suggestion.
He said: "It would impose compulsory voting on us, which is not a principle that Liberals generally support.
"Voters reveal a lot when they abstain from a democratic election or a referendum and it is important that we understand what they are telling us when they abstain or do not turn out to vote."
Mr Williamson said his comments were not a delaying tactic and that it was important to make sure the bill was "properly scrutinized" and "we don't have a situation where the future of our country is decided by 10% of the population".
He said the bill was "totally wrong".
