Opposition MPs have accused Leader of the Commons Geoff Hoon of trying to "bury bad news at sea" in timing a debate on ID cards when many are away.
Mr Hoon said he would be voting after attending anniversary celebrations.
The first vote on the government's controversial scheme is on Tuesday, the same day many MPs will mark the 200th anniversary of the Battle of Trafalgar.
Conservatives said many would find it hard to attend and said coverage would be overshadowed by celebrations.
Mr Hoon argued MPs could attend both events, as he intended to do.
Next week's debate will be the second reading of the bill and the first real test of mood since an almost identical bill was abandoned before the General Election.
The Conservatives, Liberal Democrats and some Labour MPs are expected to oppose the plans, which are likely to face a stormy passage in Parliament.
Tory MPs said many members would be marking the 200th anniversary at the International Fleet Review in the Solent, which begins the Royal Navy's commemorations of the historic battle.
Julian Lewis said media coverage of the Trafalgar event would overshadow the Commons' debate on the highly controversial ID card proposals and accused the former defence secretary of seeking to "bury bad news at sea".
Mr Hoon said he would be both taking part in the celebrations and voting at the end of the debate.
He said he was "somewhat surprised" to hear of MPs' difficulties and was sure that members would be able to watch the Fleet Review and still be back in time for the vote - at 2200 BST in the evening.
He dismissed as "conspiracy theorising" any suggestion that the two events had been put on the same day on purpose.
Last week Home Secretary Charles Clarke moved to dismiss claims that the controversial ID cards would cost £300 to buy.
The estimate was made in a report due to be published by the London School of Economics and differs from the figure of £93 put forward by the government.
Before the election 19 Labour MPs rebelled over the earlier bill on third reading. It was abandoned after the poll date was announced.