The alliance between Western Australia's Liberal and National parties continues to show signs of fracturing, as the regional party's leadership refuses to guarantee the partnership will continue to the next election.

Key points: WA Nationals won't guarantee they will partner with Liberals in 2017

WA Nationals won't guarantee they will partner with Liberals in 2017 Redman wants Nationals to be around table that "makes decisions"

Redman wants Nationals to be around table that "makes decisions" Grylls wants Labor and Liberal to outline plan for Royalties for Regions

Last month the Nationals torpedoed the Liberal's plan to sell off Fremantle Port in this term of Government, as part of a program of asset sales to help pay off record debt.

It prompted Premier Colin Barnett to say the next day he felt like he was running a minority government and the Royalties for Regions program would have to be cut back as part of the Government's fiscal strategy.

Cabinet met today in Mandurah, where both the Nationals leader Terry Redman and deputy Mia Davies cast more doubt on the strength of the Government alliance.

Neither would commit to its continuation at next year's election, with several polls showing a strong, sometimes election-winning, swing to Labor in recent months.

Mr Redman stressed the Nationals support should not be taken for granted, but said there was no reason now to suggest the alliance would not continue to the poll.

"I don't think anyone should guarantee any particular position from the National Party," he said.

"Other than to say, it's important to us that we are around the table that makes decisions that supports Western Australia.

"It's our objective to do that."

Ms Davies was equally equivocal.

"I don't have a crystal ball, but from my perspective, we're delivering very well for regional Western Australians," she said.

"We're intent and focused on doing that and we'll continue to do that."

But Mr Barnett said the alliance would "absolutely" continue.

"This has been the most stable government in Australia," he said.

"Just look at the history, federally and in every other state, we've been in government for seven-and-a-half years.

"Yes, there might be differences in opinion — every government, and even in every party, there are differences of opinion about certain things."

Come clean on future of Royalties for Regions: Grylls

Former Nationals leader and Pilbara MP Brendon Grylls told ABC 720 Mr Barnett and Opposition Leader Mark McGowan needed to be honest with regional voters and outline their plans for Royalties for Regions.

He said unlike other Government projects, the fund, capped at $1 billion a year, was enshrined in law.

"The railway to Forrestfield is not legislated spending," Mr Grylls said.

"That's a decision of Government to spend that money.

"Royalties for Regions is legislated and anyone that wants to meddle with that has to change the legislation.

"If that's Mark McGowan or Colin Barnett's plan they should raise that and say they are planning a repeal bill."