Tony Abbott has launched a defensive of his prime ministership, saying he was “confident we could have won the 2016 election with a program of budget savings and lower tax”.

“The poll-measured unpopularity of the Abbott government was not due to any shirking of responsibility but to our determination to do our duty by getting our own spending under control,” Mr Abbott says in a forthcoming Quadrant essay obtained by The Australian.

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“If governments and leaders are required always to be ahead in the polls — as well as to win elections — tough but necessary decisions will rarely be taken.”

Howard backs Abbott’s claim he could have won next election. Getty

The former prime minister has also issued a warning for Malcolm Turnbull saying his successor’s biggest challenge will be to retain popularity once he has a credible narrative of his own.

Former PM John Howard has stated his belief that ­Abbott would have won the coming election had he remained prime minister but can see why the Liberals became “nervous” and replaced him.

“I think he probably would have won it but I can understand why the colleagues got nervous. Politics is always driven by the laws of arithmetic and the arithmetic was not good at the time,” Mr Howard told The Weekend Australian.

“Politics is a tough business but it is always tougher and more ­humiliating when you are removed as a sitting prime minister after a relatively short period of time,” he said.

The former prime minister, who served for almost 11 years, advised Mr Abbott around the time of the leadership spill a year ago to appoint Malcolm Turnbull treasurer to fend off a challenge.

“Whatever will be said about Tony Abbott’s leadership of the Liberal Party, one thing will remain certain and that is nobody leading the Liberal Party in 2010 — nobody — could have done better than Tony Abbott did,” Mr Howard said.

“He went within a whisker of winning the 2010 election, which would have been a colossal historical achievement.”

– with AAP