A new survey has revealed that despite the recent passing of same-sex marriage in England and Wales, a large majority of gay Britons still live in fear of discrimination.

Gay in Britain, the new report by the gay charity Stonewall, has found that a majority of gay people would still expect homophobic discrimination if they were stand for political office, seek to foster a child, or look to become a magistrate.

The poll revealed that over 2,000 gay people said they expected their child would be bullied in primary school if it were known they had gay parents.

More than four in five expected the same if they had a child in secondary school. Seven in 10 people also expected discrimination if they were to apply to become a school governor.

Despite Prime Minister David Cameron’s recent move to legalise same-sex marriage in England and Wales, the survey also suggests that the British LGBT community still mistrusts the Conservative party.

Three-quarters think they would face discrimination from the Tories if they wanted to stand as an MP, while more than a quarter would expect the same from the Lib Dems.

Stonewall chief executive Ben Summerskill said: “Completion of our work on marriage means that one strand of Stonewall’s domestic focus – legislative equality – is effectively complete, but this polling demonstrates starkly that changing laws doesn’t change attitudes and lives overnight.”

Although same-sex marriage was passed in England and Wales, it has not yet passed in Scotland, where the Equality Network is leading the campaign for equal marriage. Stonewall is not actively campaigning for same-sex marriage in Northern Ireland. In 2009, Mr Summerskill said: “we know there are quite a lot of gay and lesbian people who wouldn’t want marriage, and some have explicitly said so.” Stonewall supported active campaigns for same-sex marriage in England and Wales after Nick Clegg and Ed Miliband had already said they supported changing the law and after David Cameron said he was open to the law changing.

The report found that one in five LGBT employees have experienced verbal bullying from colleagues, customers or service users in the past five years. A quarter said they were “not at all open” to colleagues about their sexual orientation.

On top of this, eight in 10 LGBT people would expect to face barriers if they applied to become foster parents. Almost half expected to be treated worse than a straight person by an adoption agency if they wanted to adopt a child.

Mr Summerskill said: “Gay taxpayers contribute £40bn a year to the cost of Britain’s public services. They should be able to have confidence that they will receive the services they need when accessing schools, hospitals or policing.

“It’s time the needs of this country’s 3.7 million gay people, both as citizens and service-users, were properly met.”

Stonewall said its report also showed that, in contrast to claims made by anti-gay campaigners, there has been overwhelming support among gay people for equal marriage.

Nine in 10 lesbian, gay and bisexual people support the government’s recent moves to extend civil marriage to same-sex couples.

In a speech made today at Downing Street as part of an LGBT reception last month, Prime Minister David Cameron said: “It is something to celebrate that Britain is now – and it’s official – the best place to be gay, lesbian or transgender anywhere in Europe. That is a great achievement. That’s not my measure; that is an internationally recognised measure. But there’s still a lot more work to be done.

“There’s a lot more work to be done as Britain in the Commonwealth, talking to our Commonwealth partners about decriminalising homosexuality in various countries. There’s a lot of work to be done on homophobic bullying in schools, which is still a scourge in our country.

“There’s a lot of work to be done in terms of hate crimes and how we stop and stamp that out in our society. So there’s still work to be done, but I hope we can agree we’ve taken a really important step forward.”