Same-sex marriage is a true Tory principle
Marriage not only enriches the life of the couple, it enriches society. When two people love one another, and are willing to make a lifelong commitment to each other, then society itself is strengthened.
It is precisely because marriage is such a uniquely important institution that we should ensure that all couples who want to enter into it, regardless of their sexuality, can do so.
Conservatives who believe in marriage should feel this most strongly. As David Cameron said to his own Party Conference, "I don't support gay marriage despite being a Conservative; I support gay marriage because I'm a Conservative."
Civil partnerships for gay couples were a great step forward. Entering into one was the most important thing I have done in my life. I will forever be grateful for the courage of politicians - including many Conservatives - who, against much opposition, supported this change.
But civil partnerships are not marriages. They convey almost the same legal rights, but they do not express the same universally understood commitment.
Many people say that civil partnerships should be enough. But their very opposition to what is now being proposed only underlines the point that marriage is indeed distinct.
And I have felt increasingly uncomfortable when told that I should accept something that others would not. I wonder how heterosexual married couples would feel if they were informed that they couldn't be married after all, and that a civil partnership would have to do.
I appreciate that there are some who take a different view, including many who are not homophobic but have a profound religious conviction about the nature of marriage. We must conduct this debate in a spirit of mutual respect and understanding, and with regard to the special value of religious institutions.
Religious freedom is a vitally important principle of our society. This means that religious groups should be allowed to conduct same sex marriages if they choose. Why should the state prevent the Quakers, for instance, from conducting the ceremonies they want?
Equally, it would be quite wrong to compel religious organisations to marry same sex couples against their will. The Prime Minister's unequivocal commitment to ensure this is welcome, and the safeguards should be written into the legislation itself.
It is argued that a successful legal challenge to the European Court of Human Rights could nevertheless see same sex marriages being forced on churches. This is a red herring. The European Convention on Human Rights guarantees religious freedom, and the European Court has repeatedly declined to enforce same sex marriage. In any case, ultimately our Parliament cannot be bound.
Overstating the case only causes unnecessary concern. Last week the Coalition for Marriage claimed that churches might no longer marry people at all. This is not a serious argument.
They also claimed that this change would be "massively unpopular." In fact, opinion polls consistently show strong support for it. Only one poll, conducted on behalf of the Coalition for Marriage itself, arrived at a different result, because it asked an ambiguous question about the definition of marriage.
Nor is this a narrow, metropolitan issue. Support for equal marriage holds across almost every age and social group, amongst people of faith, and in every region. Some of the highest levels of support are in the north of England.
As the Republicans found in the recent presidential elections, there is no mileage in alienating the new generation of voters or what is, even in the United States, a growing majority of public opinion. President Obama endorsed gay marriage and was re-elected. So, in London, was Boris Johnson.
Winning politicians who have built the broad base of voter support that is needed to gain office have got themselves on the right side of this argument. It is not gay marriage which will cost Conservatives votes: it is failing to win the common ground.
These are the political arguments which must be made only because some say that endorsing equal marriage will damage the Conservative Party. But politics cannot be the reason for endorsing this change, and it is certainly not why leading Conservatives from across the Party have signed up to Freedom to Marry today. We simply believe that this change is the right thing to do.
Concern is expressed that marriage is to be re-defined. But marriage has evolved over the years. Civil marriages were a major change to the institution, opposed by the churches at the time, yet without them far fewer people would get married.
Marriage will remain a lifelong commitment between two people. Making its benefits available to same sex couples would strengthen those relationships, it would strengthen society, and it would strengthen the institution of marriage itself.