A key figure in the row over Peter Mandelson’s appointment as UK ambassador to Washington will not appear before a parliamentary committee of MPs to give evidence.

Emily Thornberry had requested that Ian Collard speak to the foreign affairs committee (FAC) on Tuesday, but confirmed on Saturday that he would submit written answers instead.

The committee has already heard from Olly Robbins, the Foreign Office’s top civil servant who was forced out of his post last week after the decision to fail Mandelson during his security vetting was overruled by his department, and the Cabinet Office permanent secretary, Cat Little. Keir Starmer’s former chief of staff, Morgan McSweeney, is due to appear on Tuesday.

Collard, who has given evidence to the select committee previously, is a former ambassador to Lebanon and Panama and was appointed the Foreign Office’s chief property and security officer in March 2023.

Robbins said Collard briefed him on the vetting findings that deemed the peer a borderline case and leaned towards recommending that clearance be denied.

Thornberry has asked Collard to detail his recollection of this meeting and whether it lines up with Robbins’s evidence in a letter to the Foreign Office with questions to be answered by 5pm on Monday.

She also asked him to set out the following:

• Whether he felt under pressure to deliver Mandelson’s clearance, after Robbins said there was an “atmosphere of pressure” and “constant chasing” from Downing Street.

• Whether he had seen the cover form for Mandelson’s vetting by UK Security Vetting (UKSV), the agency responsible for checks on candidates for sensitive posts, in which it had ticked two red boxes – meaning they had “high concern” and recommended “clearance denied or withdrawn”.

• If he was asked by anyone in the Foreign Office, Downing Street or the Cabinet Office for advice about whether Mandelson required vetting for the post given that he was a member of the House of Lords.

• If he advised on how Mandelson should be treated during the period between his appointment being announced and his clearance coming through.

Thornberry wrote on X on Saturday: “To be clear, I am satisfied by the reasons behind Ian Collard not giving oral evidence before the FAC at the moment. We have therefore asked for his evidence in writing.”

She added: “If we have further questions, we will consider at that point whether we need to ask him to give evidence orally, or whether a further written statement is sufficient.”

Robbins said when he took over in the Foreign Office in January 2025, Mandelson was already being granted access to “highly classified briefings” on a case-by-case basis – without his security clearance being confirmed.

He said he had never seen the UKSV form when making the decision on Mandelson’s clearance but was briefed on the vetting.

Little told the committee there had been an initial discussion over whether the Labour grandee needed security vetting at all because he was a member of the House of Lords.

Starmer has maintained that Robbins was wrong not to have told him the outcome of the so-called developed vetting process and insisted he would not have had the peer as his top diplomat to Washington had he known.

The prime minister has stood by his decision to sack the former Foreign Office chief and said he faced only the “everyday pressure of government” to clear the peer’s appointment as ambassador to Washington in 2024.

Speaking to the Sunday Times, he said he made a distinction between “different types of pressure”.

He said: “There’s pressure – ‘Can we get this done quickly?’ – which is not an unusual pressure. That is the everyday pressure of government.”

Starmer said a pressure “essentially, to disregard the security vetting element and give clearance” would be something different, and that Robbins “was really clear in his mind that wasn’t pressure that was put on him”.

“Pretty evil” Ronnie O’Sullivan carved out a 6-2 overnight lead against his old foe John Higgins in the first session of their second-round showdown at the World Snooker Championship in Sheffield.

The seven-time winner blasted a 137 total clearance as he dominated his opponent and edged closer towards his goal of eclipsing Stephen Hendry and clinching a record eighth Crucible title.

O’Sullivan’s performance was hailed by former champion and now BBC pundit John Parrott, who said: “Ronnie was pretty evil there in amongst the balls and was definitely the best of the two players.

“Tomorrow is another day and John knows he is well capable of beating Ronnie 6-2. But John is going to have to find his top game because it doesn’t look like Ronnie is going to dip any time soon.”

Looking sharp and focused throughout, O’Sullivan dominated the session from start to finish to the extent that the Scot might have been grateful to go in overnight only four frames adrift.

O’Sullivan set about his task with a break of 86 until a rash missed pink in the second frame, which he played left-handed, gifted Higgins the chance to level things up. It proved an all-too-rare opening for Higgins, who was rendered a virtual spectator as O’Sullivan rifled breaks of 82, 137 and 92 in the next three frames.

Higgins chiselled out the sixth frame at the second attempt but normal service was soon resumed as O’Sullivan won the final two frames of the session to put himself well in control going into Sunday evening’s resumption.

Mark Allen beat the world No 2, Kyren Wilson, 13-9 to reach the quarter-finals. The Northern Irishman, who had let slip a 5-0 lead in their second-round match, won four of the six frames played in Saturday’s morning session to upset the 2024 champion.

Allen will face Barry Hawkins in the last eight after the No 11 seed defeated the three-time champion Mark Williams. The Englishman led 10-6 going into their Saturday evening session and pressed home his advantage to reach his first Crucible quarter-final for eight years. Hawkins sealed a 13-9 victory with an impressive display of his very solid all-round game.

Wilson had won six successive frames to lead 6-5 and a see-saw battle ensued before Allen won the final two frames in Friday’s session, aided by a 140 break, to edge 9-7 ahead. Wilson clawed it back on Saturday morning with a break of 78 in the opening frame, but Allen produced scores of 78 and 61 to go 11-8 up and, despite losing the next frame, held his nerve to progress.

After the match Allen made an astonishing attack on the seven-time Crucible champion Stephen Hendry for “talking rubbish”.

Hendry had strongly criticised the Antrim player’s shot selection during the opening session of the match on Thursday. But after Allen recovered to seal his victory, he turned his attention to Hendry, saying: “Stephen’s entitled to his opinion, but more often than not, he’s full of rubbish, to be honest.

“Not everyone can come here and make it look as easy as he did, but you’re also looking at someone that never won a ‘triple crown’ event after they turned 30, so the game changes and maybe that stubbornness is what cost him his later part of his career.”

Hossein Vafaei, the only qualifier to reach the last 16, fired four half-centuries to reel in Judd Trump, the world No 1, in the first session of their second-round clash, although a break of 115 in the last frame of the day ensured the former champion levelled at 4-4 overnight.

The defending champion, Zhao Xintong, will resume the final session of his match against Ding Junhui on Sunday with a slender 9-7 advantage. Zhao won five of the session’s eight frames. The winner will face Shaun Murphy in the quarter-finals.

Neil Robertson, the champion in 2010, squandered a 4-1 lead in the opening session of his second-round match against Chris Wakelin. The Australian won four frames on the spin after losing the opener, but Wakelin, the world No 13, hit back, producing a break of 77 to stop the rot and taking the final two frames of the morning session to level.