Former chancellor Rishi Sunak and Foreign Secretary Liz Truss aimed to impress party members in their first televised debate since the race to live at Number 10 was narrowed down to two.  

Mr Sunak took a swing at Ms Truss's promise to cut taxes by borrowing money.  

He said it would be nothing more than a "Sugar rush" for the economy that would be followed by a crash.

She dismissed his warning as "Project fear" and "Scare-mongering". 

Mr Sunak interrupted Ms Truss repeatedly to argue his point, with the moderator forced to interject. 

"Does anyone think that the sensible thing to do is go on a massive borrowing spree worth tens of billions of pounds and fuel inflation even further?" he asked. 

Ms Truss hit back, saying: "Crashing the economy in order to pay a debt back quicker would be a massive mistake."

There are concerns among the Conservative Party that the bitter internal fighting accompanying the leadership struggle is only benefiting the opposition Labour Party.

Former Conservative chairwoman Amanda Milling said the contest was "More toxic than I've ever seen".

In a tweet, she urged the candidates to sign up to a "clean campaign charter". 

She said without it "the lasting damage to our party could see us out of power for a decade".

Economic issues in the UK have been exacerbated by the war in Ukraine and the impacts of Brexit.

The pair are battling to succeed Mr Johnson, who quit as leader on July 7 after months of scandals triggered a mass exodus of ministers from his government.

Around 180,000 rank-and-file members of the Conservative Party will vote on who they want to lead, and the winner will automatically become prime minister.

According to bookmakers, Ms Truss is the favourite for the top job.

She outperforms Mr Sunak in polls of Conservative Party members, but Mr Sunak has the edge among voters as a whole.

Mr Johnson will remain as caretaker prime minister until his successor is announced on September 5.

The public will not head to the polls until the next general election, due by the end of 2024. 

Both candidates have ruled out giving Mr Johnson a job if they become prime minister.

"I think we need to look forward at this point," Mr Sunak said.

Ms Truss said "What's done is done" and Mr Johnson "Deserves a well-earned break". 

Sources | Reuters / AP