There'll be a fresh attempt to ban fox hunting in England and Wales for good later on Monday night.
The controversial Hunting Bill will be put to the vote in the House of Commons.
It currently bans most hunting with dogs, but fox hunting is allowed under very strict rules.
Now 145 MPs want the bill changed to a total ban on all hunting with hounds.
Pro-hunting groups are staging noisy protests outside the House of Commons.
The Environment Secretary Margaret Beckett says the existing bill is good enough and that animal welfare organisations have said it's the strongest yet.
If the bill goes through as it is, it could happen quite quickly.
But if it's changed to ban hunting altogether, it could take much longer for all the changes to be made and longer to become law.
Fox hunting is banned in Scotland.