Health Minister Peter Dutton faces a tough task convincing the Palmer United Party to support the GP co-payment.

The Palmer United Party is hardening its opposition to the GP co-payment ahead of a meeting with Health Minister Peter Dutton.

Mr Dutton will meet PUP leader Clive Palmer in Queensland on Thursday, less than a fortnight out from federal parliament returning.

With Labor and the Greens firmly opposed to the $7 GP co-payment, the government needs the support of the PUP senators to get its legislation passed.

One of the compromises being floated is exempting pensioners from the payment.

But speaking on the eve of the meeting, Mr Palmer said he had concerns about the longevity of such an exemption and remained opposed to the co-payment as a matter of principle.

“Once you start having categories and exemptions they can always be abolished,” he told reporters on the Gold Coast.

“We’ve got to realise our health care is something precious to all of us. We all need that safety net.”

Mr Palmer said he was prepared to listen to the minister, just as his party had been consulting with doctors, nurses and pensioners.

Mr Dutton said doctors supported a co-payment in principle because they wanted Medicare to be sustainable.

“I believe that, despite some of the public utterances from some of the senators, that they too want to see Medicare sustainable and they will listen to sensible arguments,” he said.

The payment is expected to save $3.5 billion over four years when it starts on July 1 next year.

Legislation has yet to be brought to parliament.

Treasurer Joe Hockey has also been speaking with all of the PUP senators on their home turf, visiting Perth for talks with Senator Dio Wang on Wednesday.

“Politics is inevitably the art of compromise, but you can’t give away your principles,” he told reporters.