The House of Lords recently overturned the decision of the Commons to lower the age of consent for gays to 16 and paved the way for the biggest constitutional clash since the election.
After an impassioned debate lasting nearly three hours, peers voted by 290 to 122, a majority of 168, to keep the age limit at 18. The free vote puts the Lords on a collision course with the Commons. It could delay for up to two years the move to equalise the age of consent at 16 for homosexuals and heterosexuals in this session of Parliament.
The vote was a further show of defiance by peers and is certain to lead to renewed demands from Labour MPs for speedy reform of the Lords, including the abolition of the voting rights of hereditary peers. Although the Lords has inflicted more than 30 defeats on the Government since the election, last night's vote was a direct challenge to the will of the Commons.
Last month, MPs voted by 336 to 129 - a majority of 207 - to lower the gay age of consent to 16. It was a free vote and the move was supported by the three main party leaders.
Lady Thatcher was among senior Tories who turned out to vote against bringing the age limit into line with that for heterosexuals. The Lords was packed for the debate amid extra security precautions in case of disturbances by gay rights activists who earlier chained themselves to Commons railings. Speeches by peers opposed to change heavily outnumbered those in favour.
Lady Young, a former Tory Cabinet minister who led the successful attempt to block the change, claimed that a majority of the population was against equalising the consent age.
Before the debate, Lady Young had received public backing from the Archbishop of Canterbury, Dr George Carey. He said Parliament would be committing a "grave error" unless it accompanied the change with stronger safeguards against child abuse.
But there was strong support for lowering the age of consent from Lady Mallalieu, the Labour life peer. She said gay sex involving teenagers was a fact of life, and said: "The law does not protect young people; it makes them criminals."
With Parliament set to start its summer break in just over a week, the Crime and Disorder Bill will be delayed if the consent issue turns into another "ping-pong" battle between the Commons and the Lords. In order to ensure that it reaches the statute book by the end of this month, ministers are understood to be ready to drop the clause. Tony Benn, the veteran Labour Left-winger, said that if the Lords defied the Commons, it would intensify the pressure for reform of the upper house.