South Cambs MP Heidi Allen has expressed her dismay on social media after Boris Johnson was announced as the new Conservative Party leader, taking office as the next Prime Minister tomorrow.

The independent MP, who defected from the Conservatives earlier this year, took to Twitter after it was confirmed that Mr Johnson had seen off competition from MP Jeremy Hunt to win the leadership contest.

In response to a tweet announcing the news, Mrs Allen wrote: "If ever I needed reminding why I left #notmypm."

Earlier this year Heidi Allen defected from the Conservatives to a new independant group, Change UK - The Independent Group, made up of Conservative and Labour MPs who had been become disappointed with Brexit politics on both sides.

She soon became the interim leader of the new party, before leaving the party last month following May's EU elections due to a perceived lack of collaboration with other anti-Brexit parties.

Royston Crow: North East Herts MP Sir Oliver Heald. Picture: Warren GunnNorth East Herts MP Sir Oliver Heald. Picture: Warren Gunn (Image: Archant)

Mrs Allen told this newspaper: "To have such a gung ho and irresponsible person as our Prime Minister at any time would be a matter of grave concern, but especially so as our country is at such a pivotal moment.

"If Boris Johnson thinks he can drag the UK out of the EU with no deal, then he is mistaken. I can assure him that Parliament will stop him from taking us down a reckless path of economic ruin.

"This is not a dictatorship and he does not speak for Parliament nor the country as a whole."

Meanwhile, North East Herts MP Sir Oliver Heald congratulated Mr Johnson, but the Conservative urged him to "adopt some of Hunt's campaign ideas",

Royston Crow: North East Herts MP Sir Oliver Heald. Picture: Warren GunnNorth East Herts MP Sir Oliver Heald. Picture: Warren Gunn (Image: Archant)

He said: "Congratulations to Boris on becoming leader of the country and the Conservative Party. I supported Jeremy Hunt during the leadership campaign and thought he came up with an interesting and beneficial set of policy ideas.

"Hopefully Boris can adopt some of the Hunt campaign's ideas, unite the party and deliver for the country."