A revolutionary Bill giving gay and lesbian partners the same legal rights as married couples will be included in the Queen's Speech with the personal agreement of Tony Blair.
The Prime Minister's decision will surprise many who believed that the Government's radical moves to create civil partnerships would take years to turn into legislation.
Under the Bill, pension and property rights will be conferred on homosexual couples for the first time - provided they agree to sign an official register of partnerships.
The changes would transform the lives of gay and lesbian people, allowing them to benefit from a dead spouse's pension, exempt them from inheritance tax on a partner's home and give next of kin rights in hospitals.
Some campaigners had worried that the plans were so controversial that they would be delayed until after the next general election but, following its inclusion in the Queen's Speech in November, the new law is expected to be on the statute books by next year at the latest.
According to Downing Street's planning "grid", a consultation paper was due to be published this Friday. But in yet another consequence of the botched reshuffle, it has been delayed until later this summer because its sponsoring minister, Barbara Roche, has been replaced as Equalities minister.
The plans, particularly to grant pension rights, were bitterly opposed by some within Whitehall but Mr Blair has agreed that the Government should act swiftly to correct generations of injustice.
Following Mrs Roche's insistence, the proposals make the civil partnership as close to a marriage contract as possible, even including provision for a form of divorce through "dissolution" of a partnership.
The scheme will not apply to heterosexual cohabitees on the grounds that they have the option of civil or religious marriage denied to homosexuals.
Contrary to speculation, there will be no requirement for couples to spend a certain amount of time living together to prove their commitment prior to a partnership. Although ministers are keen to avoid the phrase "gay marriage", the only difference from marriage will be technical provisions for break-ups of partnerships.
Ben Summerskill, the chief executive of Stonewall, the gay rights group, said: "This is desperately overdue because it involves thousands of people and real lives."
Equality campaigners have long argued that the lack of legal recognition for same sex relationships results in huge practical problems for thousands of people. Gay people can be denied information about a sick partner in hospital or involvement in their partner's funeral arrangements.
Many have been evicted or left seriously out of pocket because they are forced to pay inheritance tax on property owned by their partner. Under the new law, they would be exempt, like married couples.
Whitehall officials and equalities campaigners were dismayed by Mrs Roche's dep- arture from Government after she had taken repeated political risks to draft the proposals.
The consultation document, which included a foreword by Mrs Roche, had to be pulled back from the printers so Jacqui Smith, her replacement, could put her own imprint on it.
In a separate move, regulations outlawing discrimination against homosexuals in the workplace were approved by the House of Commons last night. The Employment Equality Regulations 2003 had been criticised by a select committee for their "doubtful" legality because they grant an exemption to religious groups to discriminate against homosexual staff.
Lord Alli, the Labour peer, said the exemption "felt like a provision drawn up by the Taliban". But Gerry Sutcliffe, the Trade and Industry Minister, told MPs that the legislation was narrowly drawn and he explicitly ruled out its application to teachers in faith schools or cleaners in churches.