The Labor and Palmer United parties have launched their WA Senate election campaigns ahead of the poll re-run in early April.

Federal opposition Leader Bill Shorten has appealed to West Australian voters to treat the Senate election re-run as a new season not a replay of last year’s political grand final.

Mr Shorten launched Labor’s campaign in Perth on Sunday while Clive Palmer was also out west drumming up support for his Palmer United Party (PUP, to extend its balance of power in the Senate.

The opposition leader urged West Australians not to give Prime Minister Tony Abbott a rubber stamp in the Senate to cut funding to Medicare, hospitals, schools and to peel back working conditions.

“This election is not the replay of last year’s political grand final,” Mr Shorten said.

“This is a new season. This is round one – and Labor is up for the contest.”

He acknowledged voters might be feeling election fatigue but declared the stakes were too high for them to stay at home.

“If you do not vote on April 5, Western Australia will be the loser,” he said, adding voters had the power to send a loud message on the first six months of the Abbott government.

Labor is hoping to win back its second WA Senate spot, for sitting Senator Louise Pratt, which was lost in the recount that followed September’s federal election.

The High Court eventually declared the state’s Senate result void after revelations 1375 votes went missing.

Mr Shorten took aim at the government’s failure to release its commission of audit, which contains plans for budget cuts, ahead of the poll.

WA voters deserved to know “what they’re being asked to vote for”.

“Imagine if I was trying to sell you a car but I covered it with a blanket, refused to tell you the mileage or describe the features – and offered an unspecified price,” he said.

“You’d walk out of the dealership. I’d be out of business tomorrow.”

Mr Shorten also warned voters about the prospect of GP co-payments, or what he called “Mr Abbott’s GP tax”.

“We believe it should be your Medicare card – not your credit card – that determines the treatment you receive,” he said.

Meanwhile, at Mr Palmer’s campaign launch in Fremantle, the Queensland MP vowed to use his support for the carbon tax and mining tax repeals as leverage to get reform on the GST for WA.

“We’re fearless… and we’ll seek that GST back for Western Australia,” he said.

It’s unfair that the powerhouse state was not receiving due rewards for its hard work, he said.

The September election delivered Dio Wang as the only PUP senator for WA before a recount saw him lose the spot and now he’s having another crack at it.

On July 1 two PUP senators-elect – sports star recruit Glenn Lazarus from Queensland and Jacqui Lambie from Tasmania – will take their places in the upper house alongside Australian Motoring Enthusiast Party senator-elect Ricky Muir who has formed a voting bloc with the party.