"After extensive consideration and stakeholder engagement, it is apparent that priority needs to be given to ensuring Tasmanian businesses big and small are competitive in global markets," he said.

"My position is about achieving the best deal for Tasmania, and strengthening Tasmania's global export markets, bolstering jobs creation, wages growth and building sustainable communities.

"In that regard, I support the Government's Company Tax Bill."

Ms Lambie opposed the tax cuts but she expelled Senator Martin from her party for refusing to give her his Senate spot after she relinquished her dual British citizenship.

The government needs nine of the 11 Senate crossbenchers to pass the bill and it intends to put the legislation to a vote before Parliament rises on Wednesday next week for Easter.

The Senate has already passed the first three stages of the 10-year tax cut plan – a lowered rate for businesses with annual turnovers capped at $50 million.

Prime Minister Malcolm Turnbull cautiously welcomed the development.

"We are seeking the support of the crossbench. It is vitally important that we provide the incentive for businesses - small, medium and large - to invest and employ," he said.

"That is why we have seen jobs growth today. We have secured reduction in business tax to businesses of up to $50 million per year in turnover. That is not a giant business. More than half of Australians work for companies that size or smaller. The fact is, we have to have a competitive tax rate.

"The US have gone to 21 per cent, we have to have a competitive company tax rate to attract investment, which will drive jobs."