ALUN Cairns, the Welsh Secretary, has resigned over claims he did not tell the truth about knowing of a former aide's role in the "sabotage" of a rape trial.

The resignation came just minutes before Boris Johnson was due to address the nation from Downing St to mark the formal start of the General Election campaign.

It threatens to overshadow the Tories' formal launch with the party leader holding a rally in the Midlands this evening.

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James Cleverly, the Conservative Chairman, was forced to take to the airwaves this morning to try to get his party's campaign back on track after the controversial comments by Jacob Rees-Mogg, which offended families of the victims of the Grenfell Tower fire.

The Commons Leader issued a profound apology after he suggested residents should have used their "common sense" and ignored the fire brigade's advice to stay put.

Mr Cleverley admitted his colleague's comments had "caused a huge amount of hurt and distress".

The senior Tory also faced questions about a campaign video featuring footage of Labour's Keir Starmer that critics claimed had been "doctored".

Mr Cleverley defended the posting, saying it was a "light-hearted satirical video".

In a letter to the Prime Minister, Mr Cairns says he is “confident” he will be cleared of any wrongdoing.

Mr Johnson’s response is brief, noting: “I am pleased to hear you will co-operate fully with the Cabinet Office during this process.”

Mr Cairns, 49, who has been a Cabinet Minister for three years, has represented the Vale of Glamorgan since 2010.

He said he had only become aware of Ross England's role in the trial's collapse when the story broke last week.

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However, it emerged that he was emailed about it in August 2018, four months before Mr England was chosen as the Tories’ Vale of Glamorgan candidate for the Welsh Assembly.

Mr Cairns tells the PM: "You will be aware of allegations relating to the actions of a party employee and candidate for the Welsh Assembly elections in the Vale of Glamorgan.

"This is a very sensitive matter and in light of continued speculation I write to tender my resignation as Secretary of State for Wales.

"I will co-operate in full with the investigation under the Ministerial Code, which will now take place and I am confident I will be cleared of any breach or wrongdoing."

In his response, the PM says he is "extremely grateful for all the work you have done in the role as Secretary of State since March 2016".

He adds: "In particular, I would like to put on record my gratitude for all the support you have given to this Government in ensuring we honour the commitment to the people that we leave the European Union.

"Given your long service as Secretary of State, you can be proud of your record of delivery for the people of Wales, in particular in ensuring the abolition of tolls on the Severn bridges."

In court, Mr England insisted he had given an "honest answer" when giving evidence at the rape trial of his friend James Hackett.

He admitted to having had a casual sexual relationship with the complainant - which she denied - despite the judge making it absolutely clear that any evidence of the sexual history of the victim was inadmissible.

The judge asked Mr England: “Why did you say that? Are you completely stupid? You have managed single-handed - and I have no doubt it was deliberate on your part - to sabotage this trial.” Judge Stephen John Hopkins told him: “Get out of my court."

Hackett was subsequently convicted of rape at a retrial.

Last week, Mr England was suspended as a Tory candidate after details of the court case emerged. The party said a full investigation would now be undertaken.