The government put plans to give gay couples the same rights as married ones back on track after winning MPs' backing for its Civil Partnership Bill.
Germany introduced similar equality legislation in 2001
Ministers also announced a pensions boost for same-sex couples, saying they would in future benefit from deceased partner's public services pensions.
The move followed pressure from all sides during a debate on the bill.
MPs approved the Bill at its second reading by 426 votes to 49. It now goes to committee stage for consideration.
Announcing the pension plans junior Scottish minister Anne McGuire said: "The change will be achieved by means of regulations which will be introduced following Royal Assent to the Bill. There is no need to amend this Bill.
"The regulations will provide equality as they will allow registered same sex
partners to accrue survivor pensions in public services schemes from 1988."
Former home office minister Barbara Roche said the plans to give gay couples the chance to attain the same legal footing as married ones showed the country was "growing up".
The issue was one of "fundamental equality and social justice", she said.
Equality minister Jacqui Smith also pledged to overturn a Lords amendment extending the rights to family members and carers.
The Commons vote did not address those amendments, but
Ms Smith said they should be stripped out before the bill gets
The changes would have led to "a myriad of legal absurdities" she said as she opened the second reading debate in the Commons.
When peers tabled the amendment in June, Labour peer Lord Alli said: "This amendment is ill-conceived and does nothing other than undermine the purpose of the Bill.
The first openly gay Tory MP, Alan Duncan, said homosexual couples were a "fact of life" and should not be "penalised".
Mr Duncan said: "This is about removing a discrimination in law which exists against them."
He gave the example of a 76-year-old-man who lost his home after his homosexual partner died because gay couples did not enjoy the exemption from inheritance tax as married couple do.
The man also had no claim on his dead partner's pension.
CIVIL PARTNERSHIP RIGHTS
Social security and pension benefits
Possible parental responsibility for partner's children
Full recognition for life assurance
Responsibility to provide reasonable maintenance for partners and children
Same tax treatment as married couples, including exemptions from inheritance tax on homes
Visiting rights in hospitals
Rebuffing arguments that civil partnerships would denigrate marriage, he said the key difference was that marriage was an institution of "religious significance" while a civil partnership is a "civil arrangement".
He urged his fellow Tory MPs to back the bill saying the proposals were "compatible with Conservatism".
Labour MP for Wallasey Angela Eagle said the amendment would create an absurd situation where blood relatives were "effectively married" in order to avoid the burden of inheritance tax.
The arrival of the Bill was "a time of celebration for many of us," the openly gay MP said.
"Same sex couples have had to live for many years with bigotry and ignorance but they have also had to live with being legally invisible."
But Tory MP for Christchurch Christopher Chope said: "If we are going to deal with relationships outside marriage why don't we deal with them all on the same basis."
But former Tory home office minister Ann Widdecombe said she believed the plans were "misconceived " and undermined the institution of marriage.
Miss Widdecombe accepted there were "unkindnesses and inequalities" in the way people in homosexual relationships were treated when compared with married
But these anomalies applied to others whose domestic arrangements placed them outside marriage.
The plans, announced in last year's Queen's Speech, follow a long campaign for equality for same sex partners.
Last June, the government suggested that up to 425,600 same-sex couples would sign up to the new civil partnerships by 2050.
But now Department of Trade and Industry officials put the figure at 42,500.
The change comes after take-up in Scandinavian countries already offering such schemes has proved much lower than expected.