VOTERS believe by a margin of more than two-to-one that David Cameron was right to declare he will not serve a third term as Prime Minister, according to a survey carried out after his shock announcement.

London mayor Boris Johnson is the clear favourite to replace Mr Cameron as Conservative leader, out of the three senior Tories he suggested might follow him into the job.

Some 68% of 1,000 people questioned online by market research company Usurv said Mr Cameron was right to make his intentions clear about a potential third term, against 32% who said he was not.

The results suggest ordinary voters may not share the reservations about the Prime Minister's openness expressed by Westminster-watchers including Michael Portillo, who branded it "bizarre", and Alastair Campbell, who said it was a "potential disaster" for the Tories.

Asked which of the three potential successors identified by Mr Cameron they would prefer as his replacement, 48% plumped for Mr Johnson, against 30% for Home Secretary Theresa May and 22% for Chancellor George Osborne.

:: Usurv questioned a selected sample of 1,000 people today. Results reflect UK gender and regional breakdowns according to the 2011 census and are post-weighted against census and HMRC data for age and income. Usurv is a member of the Market Research Society and adheres to its code of conduct.