Tory party activist Elliot Johnson, right with Mark Clarke, left, taken in October 2014

The Tories were rocked by a new scandal last night after a Cabinet Minister confessed to an affair after being told he faced a blackmail plot by a senior aide to David Cameron.

The Minister informed No 10 he had been told Tory director Mark Clarke intended to film him and his female lover leaving a London club where they met for trysts.

He ended the six-month affair in May, the same month in which his lover, who holds a high profile Conservative post, was tipped off about the alleged blackmail plot.

The Minister kept quiet until Tory activist Elliott Johnson killed himself in September after he had been bullied by Clarke – who was publicly feted by Mr Cameron after running the Party’s ‘Road Trip 2015’ campaign.

He owned up to Downing Street and Tory Party chairman Lord Feldman. He also told his long-term female partner.

The sensational disclosure comes amid panic in the Tory high command over the scandal. One party veteran said it was ‘beginning to resemble a new real-life version of House of Cards’, the 1990s TV series – recently adapted for a US version starring Kevin Spacey – involving skulduggery in the Tory Party.

The Mail on Sunday is aware of the names of the Minister and his lover but has decided not to publish them. The Minister said: ‘Mark Clarke is an appalling man – I wish I had never met him. I was stupid. I hope to repair my relationship with my partner.’

The Minister’s lover was warned that a Tory ally of Clarke, Sam Armstrong, planned to film the couple leaving the East India Club in the heart of London’s clubland so that Clarke could ‘blackmail’ the Minister to gain political favours.

Armstrong is said to be used regularly by Tory HQ to ‘dig dirt’ on rival Parliamentary candidates. He has a Commons pass issued by Thanet South MP Craig Mackinlay, who defeated Nigel Farage in May’s Election.

He said last night: ‘These accusations are preposterous and belong in a spy movie not a newspaper. My role within Road Trip 2015 was batching leaflets not blackmail.’

The alleged blackmail scandal comes after Clarke, Armstrong and another Tory crony, Andre Walker, were banned from the Tory conference when Johnson committed suicide. In addition, Clarke was suspended from the party.

Clarke, 38, was dubbed the ‘Tatler Tory’ after being tipped by the society magazine for a Cabinet career. But he faces political ruin and the risk of criminal prosecution over claims that he assaulted women Tory activists and used blackmail, alcohol, thuggery and sex-and-drugs smears in a vicious Tory Party power struggle.

Last night, Conservative chairman Lord Feldman, a close friend and political ally of Mr Cameron, vowed to expel Clarke from the party and slap a life ban on him from standing as a Conservative MP if the allegations are accurate.

A spokesperson for the peer said: ‘If the allegations against Mr Clarke are found to be true, the Party Board will permanently exclude him from the Party. There would be no prospect of Mr Clarke being allowed to apply to be a Conservative Party candidate of any kind, or represent the Party in any respect, again.’

Clarke, an executive with consumer goods giant Unilever, claims he has been targeted by Tory HQ because he threatened to expose ‘endemic drug-taking’ in the party.

Mr Clarke, bottom left, refuted any suggestion of bullying, harassment, or blackmail/attempted blackmail

In a statement to this newspaper, Mr Clarke said last night: ‘I strongly refute any suggestion of bullying, harassment, blackmail, or intended/attempted blackmail.’

The Minister told Lord Feldman in late September he had been warned he could be targeted by Clarke over his affair. He confessed after The Mail on Sunday revealed claims that Clarke had bullied Johnson, who had worked for Tory HQ during the Election.

The Minister first learned of the alleged blackmail plot in a text message from his lover: ‘I was told Clarke and Sam Armstrong were planning to take photographs of us coming out of the East India Club.’

A well-placed source said: ‘They were going to send the incriminating photo to the Minister in a plain manila envelope so they could blackmail him,’ said the source. ‘Clarke wanted political favours.’

The Tories and police are investigation a number of allegations against Clarke. They include a claim that he tried to entrap the blackmail Minister’s lover into being filmed snorting cocaine to leak it to the media.

He is also accused of blackmail and revenge porn by a young male Conservative official. The official says he was duped into performing a sex act on a fake website and asked for £2,500 to stop it being posted on his Facebook page.

When he refused, the threat was carried out. Mr Clarke made a copy of the film and tried to leak it to the media. The Mail on Sunday has seen the film, which shows Clarke recording it on a smartphone camera.

The Tory Party and police are investigating the claims surrounding Johnson’s death and other allegations about Clarke. This newspaper has learned that Clarke was quizzed before the 2010 Election by Party chairman Eric Pickles and Tory Chief Whip Patrick McLoughlin over claims of an altercation, but no action was taken.

The then Conservative chairman Grant Shapps is also in the firing line for giving Clarke the title of Tory ‘director’ when he endorsed his ‘Road Trip 2015’. It consisted of bussing young activists into key constituencies.

Clarke was lauded by Mr Cameron at an Election victory rally. The Prime Minister was furious when the full extent of the Clarke scandal was exposed. He has long described Clarke privately as a ‘nightmare.’

The timing of the disclosure is no coincidence. Clarke’s alleged victims were terrified of speaking out earlier because it would have damaged their chances of winning.

As they stepped forward, Clarke intensified his threats to try to silence them. But he pushed Johnson too far. The Tories could sweep the scandal under the carpet no longer.

'We'll nail the b*******': Parents of bullied Tory activist who killed himself vow to bring down those their son blamed for his suicide

Ray and Alison Johnson, pictured, pledged to win justice for their son Elliot who took his own life

The parents of the Tory activist who killed himself after being bullied by a senior Election aide to David Cameron have vowed to nail the ‘bastards’ his son blamed for his suicide.

Ray and Alison Johnson pledged to win justice for their son Elliott, 21, who was physically and mentally abused by Tory director Mark Clarke, head of the Prime Minister’s ‘Road Trip’ campaign.

And they want to know why Conservative chiefs failed to protect Elliott despite warnings about Clarke’s thuggish behaviour going back years.

Speaking to The Mail on Sunday at their elegant but modestly furnished Georgian home in Wisbech in the Cambridgeshire Fens, Mr and Mrs Johnson told of their agony at losing their ‘lovely, bright and brave’ son. He was found dead by a railway track after being targeted by burly Clarke, 37, and his Conservative henchmen.

While grieving, businessman Mr Johnson, 57, has spent much of the eight weeks since Elliott’s death diligently piecing together the events that led to his suicide. Convinced the Tory Party is trying to cover up the truth to protect senior figures, Mr Johnson is conducting his own investigation in parallel to police inquiries. He is convinced he is fulfilling his son’s last wish and his own dossier of evidence includes damning letters and emails from Elliott’s computer.

‘If Elliott had wanted to commit suicide all he had to do was eat a couple of peanuts: he was allergic to them. It would have killed him straight away. It makes me think he wanted to go out in a big way. I am convinced he decided if he was going to go down he would take Clarke and the other bastards with him.’

It is an uncharacteristic flash of rage from Mr Johnson, who, like his son is unassuming, intelligent and decent. But also like his son, Mr Johnson’s quiet voice masks a steely core.

‘Elliott was only 5ft 4in but he always stood up for himself,’ says Mr Johnson. ‘He loved playing rugby at school and wanted to be at the forefront of everything.’

In their search for the truth, the couple endured a harrowing ordeal, scrolling through their son’s computer entries in the days and hours leading up to his death.

They discovered how he had returned from a Tory event at the Commons on September 14 and starting trawling the internet for ways of committing suicide.

The family discovered their son's trauma after trawling though his computers following his tragic death

Eventually, he located an aerial photograph of an isolated railway track at Sandy, Bedfordshire, 50 miles from his family home, where he killed himself the next day.

‘He turned his computer off at 6.15pm to go out – until then he’d been looking at normal political stuff. He came back from the Commons at about 11.30pm and within minutes he was searching for ways to commit suicide,’ said Mr Johnson. ‘He looked at various methods – poisoning and others – and eventually settled on railways. He obviously decided “that’s the way I’m going to go.”

‘He wore a smart shirt and tie and waistcoat – he loved wearing a waistcoat,’ says Mrs Johnson. ‘He was so smart he took four suits to university,’ she smiles.

‘He had his Loake leather shoes on too, didn’t he?’ interjects her husband fondly.

‘He put a blue towel between the tracks to lie on. I suppose he didn’t want to get wet,’ Mrs Johnson continues. ‘When I saw his body in the coffin he was perfect. The only damage was to his head.’

‘We think he lifted his head at the last minute,’ says Mr Johnson, faltering. Mrs Johnson glances up at her husband as the undemonstrative English couple hold back their tears.

As meticulous as his keen historian dad, Elliott left three suicide notes: a moving apology to his parents and two sisters, and a double-edged message to ‘friends and allies’.

The third – to unnamed ‘bullies and betrayers’ – is the shortest and most telling. It says: ‘I could write a hate message. But actions speak louder than words. I was never one for hate anyway. But I think this should be on your mind.’

Mr Johnson said that at no stage did his son Elliot, pictured with Boris Johnson, show any sign of depression

Rarely has a boyish 21-year-old’s scrawled suicide note been composed with such poetic and political potency. Mr Johnson says Elliott never showed any signs of depression. Quite the reverse: only two months earlier he graduated from Nottingham University and achieved his dream, a job in London as political editor of the Conservative Way Forward magazine.

But for all his pluck, Elliott was never going to be a match for ruthless and charismatic manipulator Clarke, nearly twice his size and age. The word most use to describe Elliott is ‘sweet’; for Clarke it is usually ‘nasty’ – or much worse. One of his closest friends called him a ‘narcissistic sociopath’.

‘Elliott was a lovely boy – bright but a softie,’ says Mrs Johnson. Glancing up at her husband, she adds: ‘He had your brains and my emotions.’

Elliott’s idealism and warmth is mirrored by a photograph he clutched to him when he died: a grainy black-and-white picture of his grandfather, also called Ray, smiling while at work on a building site.

Mr Johnson explains: ‘My dad died long before Elliott was born but for some reason he idolised him. I think it was because Dad was a working man who always voted Tory. Elliott loved that. He was Elliott’s working-class hero. He had two photos of my dad and treasured them more than anything.’ When Elliott died and one of the two photos was missing from his London flat, Mr Johnson knew where it would be.

‘I asked the police if they had found an old photo by the railway track. When they said they hadn’t I asked them to look again.’ They did, and there it was, a few feet from where Elliott had died.

HIS passion for politics first surfaced as a teenager at Spalding Grammar School. In 2010 he won a mock election as the Tory candidate, thrashing rivals with 80 per cent of the vote.

‘People used to say he was our very own William Hague,’ smiles Mrs Johnson.

Five years later, Elliott’s gift for writing and campaigning was put to good use by the Tories in a real Election campaign. He was part of the party’s social media campaign team and impressed chairman Lord Feldman and chief strategist Lynton Crosby.

The Johnsons say they will not be satisfied until those who they believe led their son to take his own life are not just thrown out of the Tory Party but face criminal prosecution.

If the Conservatives and police fail to do so, they say they will consider launching a private prosecution. They say they owe it to their ‘sweet’, tragic son.