The government’s LGBT advisory panel, which suffered a series of resignations over the delay in banning conversion practices, has been officially disbanded.

Liz Truss, the equalities minister, wrote to the remaining nine serving members to thank them for their service, promising that a replacement panel would be set up. She was told the disbanding would further weaken trust among LGBT people.

The panel was established by Theresa May’s government, and the members’ terms were set to expire on 31 March. However, three panellists resigned last month, including Jayne Ozanne, who describes herself as a “gay evangelical Christian” and who is director of the Global Interfaith Commission on LGBT Lives.

She said it was “such a shame” the group was being wound up, and that disbanding it would do “nothing to rebuild trust or reassure [the] LGBT community of their grave concerns”.

“It was a force for good, where the needs of LGBT people could be heard and understood,” she said.

When Ozanne resigned, she accused the government of creating “a hostile environment for LGBT people among this administration” and hit out at an “increasing lack of engagement” with ministers acting “against our advice”.

The catalyst for her resignation was the delay in the government banning conversion practices, which it has long promised it will make illegal.

The lack of action has angered some backbench MPs. In the last Commons debate on the subject, Gary Sambrook, the Conservative MP for Birmingham Northfield, said: “I want to send a message to the government that it has been three years since this promise to ban conversion therapy. We have got to get on with it and make sure that we deliver on it.”

Boris Johnson’s official spokesperson on Tuesday defended the decision to disband the panel, saying it was “created under the previous administration and the term of all panel members was always due to end on the 31st”.

He said: “The prime minister is immensely proud to live in a country that is one of the most progressive and liberal when it comes to LGBT equality. The minister for women and equalities has written to all panel members to thank them for their contributions, and plans for a replacement to the panel will be set out in due course.”

Wes Streeting, the shadow minister for schools, said: “Well that’s one way of preventing further resignations, but it does tell the LGBT+ community exactly where we stand with this government.”

The Kaleidoscope Trust, an LGBT human rights charity, said it wanted to hear more from the government about the replacement panel, adding it hoped the new panellists would include “the voices and perspectives of civil society organisations working on behalf of LGBT+ communities across the Commonwealth”.

A government spokesperson said it was “committed to building a country in which everyone, no matter their sexuality, race or religion, is free to live their lives as they choose”, adding “we have repeatedly made clear that we will take action to end conversion therapy and we are working to bring forward plans to do so shortly”.