The Liberal government voted Tuesday to spend an additional $59 million on the controversial gun registry.

The bill was approved by two separate votes in the House of Commons. Ottawa says it needs the extra money for the program, which is expected to cost $1 billion by 2005. It is hundreds of millions of dollars over budget.

The Canadian Alliance, Progressive Conservatives and most New Democrat MPs opposed the funding.

Some backbench Liberals had threatened to vote with the opposition against the funding. But they sat out the vote after a threat by the prime minister to expel dissidents from the Liberal caucus.

Last week, up to 20 Liberals were prepared to vote against the expenditure.

Liberal whip Marlene Catterall said because the vote involved the spending of money, the prime minister considered it a vote of confidence in the government. She warned that anyone opposing the measure would face expulsion from caucus.

Liberal caucus chair Stan Keyes said many of his disgruntled colleagues changed their tune.

"You've either got to stand with the team and with the family, or you don't. I'm saying to you that there are not dozens and that there is no risk of the government going into ... a snap election on this issue," said Keyes.

Opposition members insist the gun registry is a misuse of taxpayers' money.

Canadian Alliance MP Gary Breitkreuz said costs won't stop with the $1 billion. He said the government failed to report to the auditor general how much enforcement of the law would cost.

"Today the library of Parliament reported that the costs to enforce the gun registry could be a billion dollars in the next few years," said Breitkreuz.