The leading contenders in the Conservative leadership election race have lined up to back the goal of reducing greenhouse emissions to net zero by 2050.

Front runner and former foreign secretary Boris Johnson tweeted his support for the net-zero target, which was recommended by the Committee on Climate Change (CCC) in a report last month.

He said: “A government I lead would win our bid to host COP (Conference of the Parties) 2020, legislate for net zero emissions by 2050 and embrace the opportunity of green growth for the UK as a global decarbonisation leader.

“Britain can be a world leader in delivering a greener future. We must be optimistic about our amazing potential!”

In an article in The Telegraph yesterday, Johnson wrote that market solutions offered better mechanisms than state action for tackling climate change.

Jeremy Hunt, who has attracted the second greatest number of declared MP backers after his predecessor as foreign secretary, included the 2050 net-zero goal in a five-point list of pledges for young people issued last weekend.

Responding to a questionnaire on the Conservative Home website, Sajid Javid said he accepted the CCC’s recommendation that emissions should be eliminated by the middle of this century.

He said that he would allocate a share of the £100 billion National Infrastructure Fund, which he proposed last week, to decarbonise the UK’s energy and transport networks.

And the home secretary pledged to put efforts to tackle climate change “at the heart of government”.

“I resolutely support the net-zero target. Yet without meaningful action, it’s little more than virtue signalling.”

But at the weekend he backed The Sun’s campaign to maintain the fuel duty freeze.

“Whilst it’s critical we target zero-carbon by 2050, hard-working Brits who rely on their cars shouldn’t be punished.

“Delivering vital green infrastructure will take time. Whilst we’re doing that, I’m not going to make life more difficult for hard-working families.”

Ex-Brexit secretary Dominic Raab backed “stretching targets” to cut emissions to zero by 2050.

And health secretary Matt Hancock said in a video, issued by his campaign, that there is “no price” on achieving a clean environment.

He backed a net-zero result by 2050 and the nationwide rollout of charging points for electric vehicles to drive petrol and diesel cars off the roads.