Company tax rates for small and medium-sized businesses will be slashed five years earlier than expected after Labor announced it will back the Coalition's plan to fast-track tax relief.

Key points: Government wants to move tax cuts forward five years for businesses with a turnover up to $50 million

Government wants to move tax cuts forward five years for businesses with a turnover up to $50 million On Thursday, Bill Shorten said he was keeping an open mind on fast-tracking the cuts

On Thursday, Bill Shorten said he was keeping an open mind on fast-tracking the cuts Government will introduce the legislation to Parliament next week

The Federal Government announced on Thursday that it would seek to accelerate its tax cuts for businesses with a turnover of up to $50 million.

The tax rate for those companies has already been reduced from 30 to 27.5 per cent and is scheduled to drop to 25 per cent by July 2026, but the Coalition wants to bring those tax cuts forward so that the plan is fully implemented five years earlier.

On Thursday, Opposition Leader Bill Shorten said he was keeping an open mind on the proposal and was not ruling it in or out.

Now Mr Shorten and Shadow Treasurer Chris Bowen say they have crunched the numbers and decided to support the plan.

"We're prepared to compromise in the national interest," Mr Shorten said.

Mr Shorten said he would not oppose an idea simply because someone else had it.

"The good news is that people in small and medium business enterprises can vote Labor or Liberal," he said.

"But if they vote Labor they'll be getting the same tax reductions as they would if they voted Liberal."

Mr Shorten and Mr Bowen said they would accommodate the decision in the budget bottom line by delaying the introduction of the Australian Investment Guarantee by a year.

But the Coalition has warned small businesses not to trust Labor, despite the Opposition agreeing to fast-track tax relief.

Health Minister Greg Hunt said the Coalition would welcome Labor's support on the legislation.

Later in the day, the Minister for Jobs, Kelly O'Dwyer, said the Opposition Leader couldn't be trusted because he hadn't supported tax cuts for small businesses in the past.

"Bill Shorten says, for the moment, that he supports these changes but history shows that he simply supports higher taxes on small and family-sized businesses," Ms O'Dwyer said.