Commitment to equality for gay people is an "essential element of modern conservatism", a member of David Cameron's shadow cabinet said today.
Nick Herbert, who is openly gay, admitted that the party had made "mistakes" in the past - such as imposing the Section 28 law barring the promotion of homosexuality in schools - but insisted Mr Cameron had made that a thing of the past.
He rejected claims that the Tories have not really changed, and accused the left of treating the estimated three million gay people in the UK as a "client state" whose votes could be taken for granted.
Speaking to the Cato Institute thinktank in Washington DC, the shadow environment secretary said: "For the modern Conservative Party, embracing gay equality is neither a temporary phenomenon, nor an agenda which can be reversed."
Conservative commitment to the institution of marriage was "strengthened not weakened" by including civil partnerships, said Mr Herbert.
"It's right to recognise commitment in gay partnerships," he said. "In the same way we should reject discrimination against gay couples who wish to adopt."
A Tory administration would "show leadership" in fighting homophobic abuse in sport and homophobic bullying in schools, as well as insisting on action on hate crime against gays and speaking out when countries abuse homosexuals' human rights, he said, though he stressed that this might not mean new laws.
And he said: "Conservatism is not only compatible with the principle of equality between gay and straight people but that such equality is in fact an essential element of modern conservatism."
But Liberal Democrats said there was "a gulf" between Mr Herbert's comments and the voting record of his Conservative colleagues in the House of Commons.
One in six Tory MPs who are standing at the election, including Mr Cameron and a third of his shadow cabinet, voted against the repeal of Section 28 in 2003, said the Lib Dems.
One in three voted against gay adoption in 2002 and against new regulations defining discrimination and harassment on grounds of sexual orientation in 2007. One in 10 voted against dropping the gay age of consent from 21 to 18 in 1994. And the Conservative Party has opposed provisions in the Equality Bill requiring public bodies to promote equality.
Mr Herbert acknowledged that Conservatives had driven away millions of potential supporters in the past because of their attitude to gay rights.
But he said that all three parties were now assuring homosexuals that it was "safe" to vote for them.
"Typically, far from taking pleasure in this new consensus, the Left has greeted it with dismay," he said.
"For over a decade they have sought to build a client state, where groups are beholden to their generosity. And now they want to open up 'clear pink water' between themselves and the Conservative Party.
"There's an election coming, and it suits our opponents to argue that we haven't changed. But we self-evidently have changed...
"The truth is that there are millions of people who we drove away but who share our values and want to join us.
"Gay people are not the property of the Left, or of any party. They are not an interest group or a political commodity to be traded. They are not vessels for votes.
"Gay people are motivated by the same issues as any other voter. They will vote for the political party which best sits with their views - so long as that party does not make itself taboo."
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