Lady Warsi's decision not to take part in the debate follows allegations that David Cameron banned her from attending a prominent Muslim conference in London last weekend.
She personally paid for potential customers, one of whom was in negotiations over a deal with her firm, to attend a Conservative Party lunch with the Prime Minister last month.
The Sunday Telegraph has also learnt that her business partner, Abid Hussain, a former activist with a radical Islamic group who has a conviction for violence, secured an invitation to meet David Cameron at Downing Street, raising questions over the Prime Minister's security.
A man who had once been a prominent activist in Hizb ut Tahrir, a group which wants Britain to be run under stritct Islamic law, shook hands with David Cameron in the drawing room of 10 Downing Street.
It was a moment that, for Abid Hussain, must live long in the memory.
He was standing in the drawing room of No10 shaking the hand of the Prime Minister.
It was an extraordinary turn of events for a man who had once been a prominent activist in Hizb ut Tahrir, a group which wants to overthrow Britain’s democracy and replace it with a state run under strict Islamic law.
He was introduced to David Cameron at an event to celebrate the festival of Eid which had been organised by Downing Street with the help of Baroness Warsi, the Conservative Party co-chairman, and her office.
Whether it was the Cabinet minister who put his name on the guest list for the event in November 2010 is unclear, but what was not known at the time was that Mr Hussain was actually Lady Warsi’s business partner: they are the joint owners of a company.
Mr Hussain, a second cousin of Lady Warsi’s husband, had also recently returned from Pakistan where he “assisted” her and the British high commissioner on a ministerial visit.
There are now questions about whether Downing Street knew two other facts about the man given access to the Prime Minister and the heart of government: firstly, that he was involved in an extremist group that Mr Cameron had pledged to ban, and secondly that he has a conviction for a violent assault during his younger days in Sheffield.
Whatever the answers to those questions, Mr Hussain attended another reception with Mr Cameron last month, when Lady Warsi invited him to the launch of the Conservative Friends of Pakistan, a party interest group designed to foster better understanding with the Asian nation and the huge Pakistani community in Britain.
Lady Warsi paid for Mr Hussain and her husband, Iftikhar Azam, to bring a group of business contacts of their firm, Rupert’s Recipes, to the fund-raising lunch at the Savoy Hotel in the Strand.
The launch was planned by Lady Warsi with the help of her special adviser Naweed Khan and her personal assistant Gulsum Aytac, who between them had written the Friends of Pakistan group’s mission statement and strategy and drawn up its structure.
The final guest list was a who’s who of wealthy and successful British Pakistanis.
Entrepreneurs, bankers, property developers and diplomats all paid between £2,000 to £5,000 for a table alongside Mr Cameron and Yousuf Raza Gilani, the Pakistani prime minister.
On table 15 were eight guests of Rupert’s Recipes, the Sheffield spice supply business which, company documents published in February show, was 60 per cent owned by Lady Warsi.
Mr Azam sent the names of the guests to Conservative Central Office using his Rupert’s Recipes email account. Lady Warsi sat on the VIP table with Mr Cameron and Mr Gilani.
On the Rupert’s Recipes table was Mr Hussain and Mohammed Johngir Saddiq — “Big John”, the millionaire boss of a chain of Birmingham fish and chip shops bearing his nickname.
The photographers captured a smiling and laughing Mr Saddiq with his arm around Mr Hussain.
Other guests included Fareed Nasir, the owner of Chunky Chicken, a fast food franchise with outlets across the North West, the Midlands, Cardiff and Newcastle upon Tyne, several other Asian restaurateurs and the owner of a leading halal meat wholesaler.
Whether business was discussed as Lady Warsi’s guests enjoyed a three-course lunch, with a vegetarian starter, breaded chicken main course and a kheer rice pudding with ice cream, is not known.
But several of those invited to accept the minister’s hospitality were certainly in a position buy the spices and fried chicken and fish mixes in which Rupert’s Recipes specialises — and Mr Nasir says he was in negotiation to do precisely that.
For Lady Warsi the day was a triumph. She looked relaxed and happy as she stood alongside her husband, and with her mother and father and sisters, who were also invited and sat on a second table paid for by the minister.
She told the gathering that it was “obvious that a modern progressive Conservative Party should reach out to say that our relationship with British Pakistanis should be broader and deeper, that our relationship with Pakistan should be broader and deeper, and that the Conservative Party should become the natural home of many many enterprising Pakistanis”.
In response, Mr Cameron described Lady Warsi as an “extraordinary political talent”, thanking guests for coming to an event at which, he said, “the majority of the Cabinet” were present.
He added: “I am proud that I am the first British prime minister to have a Muslim woman in my Cabinet.”
But by mixing business with politics, by failing to declare her business activities, and by allying herself with a business partner with a dubious past, Lady Warsi may have put that place in history in doubt.