Among the described amendments to the Workplace (Protection from Protesters) Bill were changes to the definition of business premises so only industries deemed to be vulnerable to protest action - mining, forestry, agriculture, construction and manufacturing activities - were included.

Mandatory prison sentences were removed for summary offences, which will also carry a lower penalty, though remained for "indictable offences".

A definition was not provided for what those offences would be.

Police will also deliver warnings to people before issuing infringement notices to protesters or taking further action.

Resources Minister Paul Harriss said the changes helped protect "mum and dad" protesters.

" We have always said that this bill is not about limiting the rights of free speech or peaceful protest," he said.

"Rather, this is about those radical few for whom voicing their opinion is not enough; who instead have such arrogance and contempt for the rights of others that they act to physically stop a business from operating."

But Greens justice spokesman Nick McKim questioned the timing of the release.

"Dropping amendments out at just before 5pm prior to a public holiday (Hobart Show Day) is effectively a confession that Mr Harriss knows that they do not address the major concerns raised by a range if stakeholders," he said.

"These desperate and minimalist amendments do not fix the bill, and arguably make it more likely to be struck down by the High Court."

Opposition deputy leader Michelle O'Byrne said the party needed time to assess the amendments.

"The government claimed its original bill was without flaws but today's announcement shows that clearly wasn't the case," she said.

Rumney MLC Tony Mulder congratulated the government for listening to the concerns of the Legislative Council, which had earlier rejected the bill on the grounds it was "poorly written and deeply flawed".

But Mr Mulder suggested there were still gaps in the proposal.

"There are unincorporated organisations organising protest action," he said.

"There should be specific offences and minimum penalties for incitement by individuals who hold themselves to be spokespeople for unincorporated groups."

The bill is expected to be debated by the Legislative Council in the coming weeks.