An email from Prime Minister Tony Abbott's chief of staff, Peta Credlin, to backbench MPs has triggered speculation that an early election could be in the offing.

The email to members and senators, obtained by the ABC and verified by Fairfax Media, suggests that Coalition MPs may wish to update their "working photographs with the Prime Minister this week to use in local electorate materials".

Ms Credlin goes on to say that a time has been created in the Prime Minister's programme between 4pm and 5pm for "any MP wanting an updated photograph".

Mr Abbott, for his part, played down the prospect of an early election on Thursday, telling people speculating about an early poll to "have a Bex and a good lie down".