John Houghton said the bill was "completely indecent"
An Isle of Man MHK has stood by comments he made about the rights of transsexuals in the House of Keys.
John Houghton was the only member to oppose a bill which would allow transsexuals to have their new gender recognised under Manx law.
He provoked anger from a number of his colleagues when he claimed proposed new laws defied "common decency".
A spokesperson for The Gender Trust said Mr Houghton was "clearly a man who knows nothing about the real issues".
The house voted 21 to one in favour of giving the Gender Recognition Bill 2008 its second reading.
Mr Houghton, the MHK for Douglas North, told Manx Radio: "It's completely indecent.
"This is a gender recognition bill [and] what that means is legalising people to have sex changes. To change their gender.
"If somebody wants to go and have an extremely unusual operation like this elsewhere, further afield, let them do so.
"But don't make a law stating you can, and then you can have it on the NHS."
The spokesperson for the Gender Trust added: "There are a lot of people still living in the Stone Age, and he is obviously someone who doesn't know anything about this.
"Gender dysphoria is a recognised clinical condition and has been for many years.
"He needs to get his facts right before he starts making comments."
The Gender Recognition Bill 2008 is based on similar legislation introduced in the UK.
Under the bill, a person who has had a sex change operation and has a full gender recognition certificate will have their new status recognised.
The UK legislation is the Gender Recognition Act 2004 (of Parliament) which has been in force since April 2005.
Eddie Teare, the island's health minister, said the operation is available on the NHS in certain circumstances, but would never be carried out in the island because it is so specialised.