The row tearing apart the People’s Vote campaign has been further escalated, as PR guru Roland Rudd moved to remove Peter Mandelson and two other directors from the board of one of its constituent organisations.

Lord Mandelson hit back in a joint letter urging his friend of 30 years’ standing to “put country before ego” and step down immediately as chair of Open Britain to aid the battle for a second EU referendum.

People’s Vote was thrown into disarray at the end of October after Mr Rudd sacked director James McGrory and communications chief Tom Baldwin just days after they helped organise a successful march which brought hundreds of thousands of people onto the streets of London to demand a referendum. The move sparked a staff walkout which paralysed the campaign’s activities just as the general election was getting under way.

Plans for a potentially crucial, tactical voting-app to help pro-Remain candidates win seats were put on hold, as staff were locked out of offices and a new chief executive installed, only to step down days later over harassment allegations, which he denies.

In their letter, Open Britain directors Lord Mandelson, Will Straw and Joe Carberry accused Mr Rudd of “doing Boris Johnson’s work for him” by provoking divisions within the People’s Vote movement and causing a breakdown in relations with other pro-EU campaigns.

People's Vote march – demanding vote on final Brexit deal Show all 30 1 /30 People's Vote march – demanding vote on final Brexit deal People's Vote march – demanding vote on final Brexit deal Mandatory Credit: Photo by Guy Bell/REX (9725259aq) Marching down Whitehall - People's March for a People's Vote on the final Brexit deal. Timed to coincide with the second anniversary of the 2016 referendum it is organised by anti Brexit, pro EU campaigners. People's March for a People's Vote, London, UK - 23 Jun 2018 Guy Bell/REX Rex People's Vote march – demanding vote on final Brexit deal Demonstrators carry banners and flags as they participate in the People's March demanding a People's Vote on the final Brexit deal, in central London on June 23, 2018, the second anniversary of the 2016 referendum. Tens of thousands of people demonstrated in London on Saturday calling for a second vote on Britain's departure from the European Union. / AFP PHOTO / Niklas HALLE'NNIKLAS HALLE'N/AFP/Getty Images NIKLAS HALLE'N AFP/Getty Images People's Vote march – demanding vote on final Brexit deal A young protestor shouts as she takes part in the People's Vote demonstration against Brexit Getty Images People's Vote march – demanding vote on final Brexit deal A woman holds a placard as she joins EU supporters, calling on the government to give Britons a vote on the final Brexit deal, participating in the 'People's Vote' march in central London, Britain June 23, 2018. REUTERS/Henry Nicholls HENRY NICHOLLS Reuters People's Vote march – demanding vote on final Brexit deal epa06833888 Pro-EU demonstrators take part in a People's March anti-Brexit rally in Parliament Square in London, Britain, 23 June 2018. Protesters are calling for a referendum on the final deal. The protest is taking place on the second anniversary of the Brexit referendum. EPA/ANDY RAIN ANDY RAIN EPA People's Vote march – demanding vote on final Brexit deal A protester's pro-EU t-shirt EPA People's Vote march – demanding vote on final Brexit deal epa06833892 A pro-EU demonstrator waves a European Flag during a People's March anti-Brexit rally in Parliament Square in London, Britain, 23 June 2018. Protesters are calling for a referendum on the final deal. The protest is taking place on the second anniversary of the Brexit referendum. EPA/ANDY RAIN ANDY RAIN EPA People's Vote march – demanding vote on final Brexit deal Demonstrators carry banners and flags as they participate in the People's March demanding a People's Vote on the final Brexit deal, in central London on June 23, 2018, the second anniversary of the 2016 referendum. Tens of thousands of people demonstrated in London on Saturday calling for a second vote on Britain's departure from the European Union. / AFP PHOTO / Niklas HALLE'NNIKLAS HALLE'N/AFP/Getty Images NIKLAS HALLE'N AFP/Getty Images People's Vote march – demanding vote on final Brexit deal epa06833960 Tens of thousands of people march through London during a People's March anti-Brexit demonstration in London, Britain, 23 June 2018. Protesters are calling for a referendum on the final deal. The protest is taking place on the second anniversary of the Brexit referendum. EPA/ANDY RAIN ANDY RAIN EPA People's Vote march – demanding vote on final Brexit deal Leader of the Liberal Democrats, Vince Cable speaks during the People's March demanding a People's Vote on the final Brexit deal, in central London on June 23, 2018, the second anniversary of the 2016 referendum. Tens of thousands of people demonstrated in London on Saturday calling for a second vote on Britain's departure from the European Union. / AFP PHOTO / Niklas HALLE'NNIKLAS HALLE'N/AFP/Getty Images NIKLAS HALLE'N AFP/Getty People's Vote march – demanding vote on final Brexit deal epa06833964 A young pro-EU demonstrator takes part in a People's March anti-Brexit rally in Parliament Square in London, Britain, 23 June 2018. Protesters are calling for a referendum on the final deal. The protest is taking place on the second anniversary of the Brexit referendum. EPA/ANDY RAIN ANDY RAIN EPA People's Vote march – demanding vote on final Brexit deal Gina Miller and Caroline Lucas EPA People's Vote march – demanding vote on final Brexit deal epa06834044 Tens of thousands of people march through London during a People's March anti-Brexit demonstration, in London, Britain, 23 June 2018. Protesters are calling for a referendum on the final deal. The protest is taking place on the second anniversary of the Brexit referendum. EPA/ANDY RAIN ANDY RAIN EPA People's Vote march – demanding vote on final Brexit deal epa06833264 Thousands of people march through London during a People's March anti Brexit demonstration in London, Britain, 23 June 2018. Protesters are calling for a referendum on the final deal. The protest is taking place on the second anniversary of the Brexit referendum. EPA/ANDY RAIN ANDY RAIN EPA People's Vote march – demanding vote on final Brexit deal Tens of thousands of people march through London EPA People's Vote march – demanding vote on final Brexit deal epa06833265 Thousands of people march through London during a People's March anti Brexit demonstration in London, Britain, 23 June 2018. Protesters are calling for a referendum on the final deal. The protest is taking place on the second anniversary of the Brexit referendum. EPA/ANDY RAIN ANDY RAIN EPA People's Vote march – demanding vote on final Brexit deal Demonstrators at the People's Vote March Getty People's Vote march – demanding vote on final Brexit deal 'Two months too young to decide on my future' REUTERS People's Vote march – demanding vote on final Brexit deal Crowds taking part in the People's Vote march for a second EU referendum at Trafalgar Square in central London. PRESS ASSOCIATION Photo. Picture date: Saturday June 23, 2018. See PA story POLITICS Brexit. Photo credit should read: John Stillwell/PA Wire John Stillwell PA People's Vote march – demanding vote on final Brexit deal A young girl joins in the march PA People's Vote march – demanding vote on final Brexit deal An EU flag is draped across the statue of Winston Chruchill in Parliament Square REUTERS People's Vote march – demanding vote on final Brexit deal Demonstrators gather prior to the start of the People's March demanding a People's Vote on the final Brexit deal, in central London on June 23, 2018, on the second anniversary of the 2016 referendum. / AFP PHOTO / Niklas HALLE'NNIKLAS HALLE'N/AFP/Getty Images NIKLAS HALLE'N AFP/Getty Images People's Vote march – demanding vote on final Brexit deal Vince Cable MP, Pro-EU campaigner Gina Miller, Tony Robinson and Caroline Lucas MP join with crowds PA People's Vote march – demanding vote on final Brexit deal Crowds gather on Pall Mall in central London, during the People's Vote march for a second EU referendum. PRESS ASSOCIATION Photo. Picture date: Saturday June 23, 2018. See PA story POLITICS Brexit. Photo credit should read: John Stillwell/PA Wire John Stillwell PA People's Vote march – demanding vote on final Brexit deal Crowds gather on Pall Mall PA People's Vote march – demanding vote on final Brexit deal A man resembling Britain's Foreign Secretary Boris Johnson, joins EU supporters Reuters People's Vote march – demanding vote on final Brexit deal EU supporters, calling on the government to give Britons a vote on the final Brexit deal, participate in the 'People's Vote' march in central London, Britain June 23, 2018. 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They insisted that their removal as directors of Open Britain – which forms part of People’s Vote alongside the European Movement, Joint Media Unit, Our Future Our Choice and For Our Future’s Sake – was not “legitimate”.

They accused Rudd of using his personal control over the company behind Open Britain in a “crude corporate manoeuvre” to remove them.

And they alleged that a company controlled by Mr Rudd had taken control of personal data relating to millions of people who gave their details to the referendum campaign. They called on him to clarify how he intended to use the data.

In any other circumstances, Mr Rudd’s failings would have led to his resignation or removal as chair of Open Britain, said Mandelson, Straw and Carberry.

Claiming that he had agreed 11 weeks ago to step aside in favour of a female chair, they said: “It is extraordinary that instead today you are seeking to remove us.”

A source close to Mr Rudd said that there would be no response to the letter, released to The Independent as the Open Britain board met.

In their letter, Open Britain directors Lord Mandelson, Will Straw and Joe Carberry accused Mr Rudd of ‘doing Boris Johnson’s work for him’ (EPA)

Infighting within the People’s Vote campaign first broke into the open with reports last month that Mandelson and former Labour communications chief Alastair Campbell were trying to remove Mr Rudd from his position at the top of Open Britain – the group set up as a successor to the Britain Stronger in Europe campaign following Remain’s defeat in the 2016 referendum.

This was swiftly followed by the shock dismissal of McGrory and Baldwin and the appointment of Patrick Heneghan, who this week stood down to fight allegations relating to his treatment of female staff.

Mandelson, Straw and Carberry condemned the manner of the sacking of senior People’s Vote staff as “unnecessary and inflammatory and an abuse of your position”.

Its consequence was to “disable the PV campaign at this crucial moment, which we can assume was deliberately timed”, they told Mr Rudd.

Mr Rudd had “exacerbated an already heated situation” by failing to attend a staff meeting which he had called, and then addressing them the following day in the presence of security guards, they said.

Plans for a potentially crucial, tactical voting-app to help pro-Remain candidates win seats have been put on hold (Getty)

And they accused him of waiting 11 days after hearing of allegations against Mr Heneghan – before suspending him as interim chief executive – and then failing to consult other parts of the PV campaign before appointing a successor.

They said he had “scuppered” plans for a new governance arrangement for PV which would have brought prominent political figures like Michael Heseltine, Margaret Beckett and Dominic Grieve on board.

Appointments he made to the board were drawn from the “so-called metropolitan elite” and meetings were held irregularly in order to “push through changes that increase your control”, they claimed.

“You are making it up as you go along, lurching from one crisis to another,” wrote the trio.

“You have contributed little to the strategy of Open Britain, preferring to use board meetings to focus on structures and corporate manoeuvres. You have not produced any funding for over six months for the campaign, leaving it reliant on the generosity of grassroots donors.

“Nor have you spent much time with the team in Millbank, as demonstrated by your failure to identify the names of most members of staff at your meeting on 29 October.

“Your actions this summer, culminating in the unilateral firing of James McGrory and Tom Baldwin on the eve of the general election, have done Boris Johnson’s work for him. He could not have hoped for a more complaint advocate on the Remain side and owes you a debt of gratitude.”