Champions of Kemi Badenoch believe the new Conservative leader will electrify Prime Minister’s Questions and create a weekly nightmare moment for Sir Keir Starmer.

Insiders are delighted by her debut last week and say the first showdown demonstrated the Prime Minster “doesn’t know how to pivot from his script”.

The high-pressure outing on Wednesdays at noon are considered crucial to establishing Mrs Badenoch’s credibility as an alternative leader of the UK.

Former deputy foreign secretary Andrew Mitchell said: “Kemi will dominate PMQs because she has the crackle of electricity and excitement and fizzes with thoughtful ideas. This will be more compelling than Sir Keir’s legal style and schtick.”

There was also concern on the Labour benches after last week’s clash between the leader of the opposition and the PM.

A Labour MP said: “I think he was very, very rattled. He was tripping over his words.”

Nick Wood, a former Tory communications director who helped then-leaders William Hague and Iain Duncan Smith prepare for their showdowns with Tony Blair, said performing well in PMQs is “vitally important” to establish credibility with Conservative MPs and with the electorate.

He said: “If you can’t hack it in the House of Commons, where are you going to hack it?”

Commenting on Mrs Badenoch’s performance, he said: “It seems to me she passed this first vital test.”

Mrs Badenoch, dressed in bright blue, used the occasion to brand Labour’s plan to restrict inheritance tax relief on the sale of agricultural land the “cruel family-farms tax”.

A Badenoch ally said: “Starmer didn’t know what had hit him. He read out his pre-prepared answers but looked like he wanted to be anywhere else.

“The way the PM floundered on the farm tax demonstrated that he simply doesn’t know how to pivot from his script, which will be useful in the coming weeks. We all knew Kemi would be a struggle for him, and it really showed on Wednesday.”

Newly-elected Conservative MP Peter Bedford said: “Her candid and direct approach will ensure that those who feel that the political class haven’t spoken for them over recent years have a strong voice week in week out at the despatch box.”

Successful prime ministers have admitted to feeling fear ahead of PMQs.

Mr Blair described it in his memoirs as the “most nerve-racking, discombobulating, nail-biting, bowel-moving, terror-inspiring, courage-draining experience”.

Tory MP Gregory Stafford said: “PMQs has seriously stepped up a gear with Kemi leading the charge.”

And fellow Conservative MP Sir Bernard Jenkin said: “She has not stopped since before the general election, but she showed no sign of fatigue and was as cool and unphased as could be. She is fearless and precise in her questions.

“Keir tried to put her down but he just looked patronising – not a good look. But we are coming from miles behind and it will take time to develop serious policy.”