The Transport Workers' Union says more than 250 workers will strike for 24 hours on Wednesday at Sydney, Melbourne, Avalon, Brisbane, Cairns and Adelaide airports.

The union has accused the airline of proposing an agreement "designed to keep Jetstar workers impoverished".

But Jetstar chief executive Gareth Evans on Friday criticised the TWU for deciding to "disrupt tourism and aviation at a time when the tourism industry and the economy as a whole - small business, tourism-related businesses, small towns - are doing it very, very tough".

Mr Evans said the airline is still determining how services will be affected but he thinks there will be some cancellations.

"We believe that our international business will be fairly unaffected; we're working through the implications for our domestic business," he said.

"The focus though, of course, is on our customers and very much minimising the disruption for those customers and getting them away on their journeys as quickly as possible."

The TWU's previous demands included more rest breaks, a guaranteed 12-hour break between shifts, a guaranteed 30 hours of work a week and annual wage increases of four per cent.

The union says Jetstar's proposed agreement would allow the company to demote staff without consultation, make it more difficult for them to take personal leave, and reduce redundancy payments.

But Mr Evans said the offer included a three per cent annual pay rise as well as back pay and other benefits around rostering and allowances.

He said the company's "best and final offer" would go to a vote sometime next week.

"We believe this is a very, very fair package in the circumstances," he said.

"The current rate of private sector wage growth is about 2.4 per cent, so this is well above that and well in excess of what most other businesses are offering."

TWU national secretary Michael Kaine said the decision to strike was not taken lightly but Jetstar management had behaved in a "belligerent" way and ignored "the genuine offer of its workforce to work co-operatively together to get better terms and conditions".

He said the airline had shut down negotiations by informing staff earlier in the week that they were putting an agreement out for a vote.

"(The agreement) says to those workers and the Jetstar workforce: we want to have more right to demote you, we don't care about your genuine claims of job security, we're not bothered that you're the lowest paid in the industry," Mr Kaine said.

"It's a ransom note because they said that if the workers do not accept this agreement, they will not pay them back-pay to March last year."

He called for Jetstar to come back to the table.

Jetstar workers went on strike twice in December.

Customers set to travel on February 19 would be provided with a full refund or flight reschedule if requested.

Australian Associated Press