The depth of the rift within the Conservative Party over Europe has been exposed by a former minister's furious response to the absence of a Sovereignty Bill in the Government's agenda for the coming year, set out by the Queen in her annual address to Parliament.
Former cabinet minister and prominent Leave campaigner Iain Duncan Smith accused David Cameron of ditching the proposal - along with other key elements of the Tories' programme - in order to improve the chances of a Remain vote in the June 23 referendum.
With the political world gripped by the struggle over EU membership, the Queen's Speech set out a relatively modest agenda of 21 bills which focused on reforms to prison, adoption and universities and largely avoided the kind of contentious legislation which might fuel opposition to the government during the referendum period.
Reading out the Speech amid the traditional lavish ceremony of the State Opening of Parliament, the Queen made only a fleeting direct reference to the subject dominating politics, stating simply that her Government "will hold a referendum on the membership of the European Union".
In what may be seen as an attempt by Mr Cameron to signal that remaining in the EU does not mean giving up the UK's independence, she added: "My ministers will uphold the sovereignty of Parliament and the primacy of the House of Commons."
But there was no mention of a Sovereignty Bill to assert the primacy of UK courts over the European Court of Justice in Luxembourg, which was floated as a constitutional safeguard during the Prime Minister's renegotiation of Britain's EU membership earlier this year.
Mr Duncan Smith - who quit the Cabinet in March shortly after declaring he would campaign for EU withdrawal - described it as the latest in a string of climbdowns aimed at smoothing the way to a Remain vote.
"Many Conservatives have become increasingly concerned that in the Government's helter-skelter pursuit of the referendum, they have been jettisoning or watering down key elements of their legislative programme," said the former work and pensions secretary.
"Whether it is the Trade Union Bill or the BBC Charter proposals, it seems nothing must stand in the way of winning the referendum.
"Yet to compound that, now it appears the much-vaunted Sovereignty Bill, key to the argument that the PM had secured a reform of the EU, has been tossed aside as well.
"The fear in Government must be that, as no-one in Britain buys the idea that the EU has been reformed, the Sovereignty Bill would draw the public's attention back to that failure. After all if the EU Court of Justice is supreme and can strike down our laws, the British people would have just laughed at the idea Britain can be sovereign unless we leave the EU."
Although he never publicly committed the Government to legislation to assert UK sovereignty, Mr Cameron said earlier this year that there was "a good case" for such a bill. In what was seen as a last-ditch effort to woo Boris Johnson over to the Remain camp, he told MPs in February that he was ready to take action to "put beyond doubt that this House is sovereign".
The row over sovereignty is likely to divert attention from the programme set out in the Speech, which committed the Government to a high-tech future Britain of spaceports, driverless cars and drones, as well as reforms to improve the life chances of the most disadvantaged.
As widely trailed, a Prison and Courts Reform Bill gives governors new powers to control their own jails, as well as an overhaul of education and rehabilitation programmes which ministers described as the "biggest reform of our prisons since Victorian times".
A Higher Education and Research Bill will make it easier to open new universities, and the academy schools programme will be expanded by an Education for All Bill - though not extended to every school in England as Mr Cameron initially planned.
Court guidelines will be altered by a Children and Social Work Bill in favour of permanent adoptions, and children in care will be given a new "covenant" setting out local authorities' duties to help them with housing, jobs and healthcare after they leave care.
A raft of measures in a Counter-Extremism and Safeguarding Bill is designed to crack down on extremism, including stronger powers to disrupt radicals' activities and to intervene in unregulated schools which are "teaching hate". Ministers will consult on a new civil order regime to restrict extremist activity.
As expected, the speech set out plans for a British Bill of Rights to replace the Human Rights Act and proposals to recoup money from foreign nationals using the NHS.
It included legislation to establish the Help to Save scheme and Lifetime ISA to encourage saving as well as measures to make it easier to access money contained in pension pots. And it confirmed the Government will legislate to impose a tax on sugar-laden fizzy drinks.
It also confirmed the Government's intention to renew the UK's Trident nuclear deterrent system, though ministers gave no clue on whether a vote on new submarines - which could potentially split Labour - will take place during the coming year, stating only that one can be expected before the next general election.
Measures to boost the economy included an Infrastructure Bill to speed the planning process and a Local Growth and Jobs Bill to allow councils to keep and invest all the business rates they raise. A Digital Economy Bill will give households a legal right to high-speed broadband connections.
In a statement released as the Queen delivered her address to MPs and peers in the House of Lords, Mr Cameron said: "This is a One Nation Queen's Speech from a One Nation Government. It sets out a clear programme of reform, using the strength of our economy to deliver security for working people, increase life chances for the most disadvantaged and strengthen our national security."