Federal parliament on Thursday agreed to back three changes to electoral laws, but a fourth proposed reform dealing with charities has been put on hold.

Under one bill, small parties will need to provide evidence of 1500 members rather than the current 500.

The same bill tightens rules around the registration of party names which replicate a word in the name of an existing registered party.

The Greens opposed the registration change, saying it will stifle the voice of smaller parties, entrenching the two-party system.

Independent senator Jacqui Lambie said she was "disgusted" by the changed rules, which would undermine democracy.

Labor supported a change to the rules to impose a fixed pre-poll period of up to 12 days before an election.

A further change will provide for a jail term of up to three years for "interference with political liberty", such as violence, property damage, harassment or stalking in relation to an election.

However, the government has put on hold a more controversial bill to reduce the amount of "electoral expenditure" an individual or organisation can spend before they are required to register as a political campaigner.

This amount will decrease from the current $500,000 to $100,000 during the financial year, or for any of the previous three financial years.

The government argues it will bring groups closer in line with the transparency imposed on political parties, candidates and MPs.

But charities say they are not like parties and the move would effectively silence community voices.

Australian Associated Press