Prime Minister Scott Morrison has sent letters to former members of the Liberal Party, pleading for them to rejoin ahead of the federal election.

"I wanted to write personally and encourage you to rejoin the Liberal Party."

"We need everyone who believes in our values to become energised members of our movement," he writes.

PM Scott Morrison, pictured today with Bonner MP Ross Vasta in the carpark of Esida Lodge Aged Care in Brisbane today. (AAP)

A copy of the letter which was sent out by the PM. (Supplied)

The letter was signed by Mr Morrison, who was today on the campaign trail in Brisbane, and authorised by NSW Liberal Party State Director Chris Stone.

It was a captain's pick by the Prime Minister, which sparked the resignation of the dumped locally-endorsed Liberal candidate Grant Schultz, along with a number of disillusioned Liberal Party branch members.