Liberal MPs are invoking a procedural delay on the Conservatives' omnibus crime bill, debating a change to the proposed package of justice reforms that would end its passage through the House of Commons.

The NDP and Liberals are against the bill, which wraps a number of proposed laws into one package that the government wants to pass all at once.

Liberal MP Sean Casey has proposed an amendment that would delete every page in the bill and replace it with a vow not to pass it on to the next stage in Parliament.

If passed, the Liberal amendment says MPs are declining to move the bill forward because it ignores the best evidence on public safety, crime prevention and rehabilitating offenders, the government hasn't provided a clear cost estimate, and bundling that much legislation together "will compromise Parliament's ability to review and scrutinize its contents and implications on behalf of Canadians."

This is the second proposed change, known as a reasoned amendment, the Liberals have proposed since Monday.

The debate on the amendment will continue until no more MPs want to debate it. It is due to continue Thursday.

Conservative MPs outnumber MPs from other parties, which should allow them to pass the legislation once it gets to a vote.