Organisers of the Norwich Pride march have told members of the city's Labour group they must not display the party's flag at the event this afternoon.
Today, thousands of people are set to make the city awash with rainbow colours as the annual celebration of the LGBT+ community is held.
But as the festivities get under way, the Norwich Labour group has been told its flag can not be flown during the parade amid growing anger directed at new health secretary Wes Streeting.
In a statement posted on the event's website, organisers said: "We are gravely disappointed with the approach of Wes Streeting, who has recently backtracked on saying that trans women were women - and has continued the ban on puberty blockers.
"Because of this, we feel that although local members will be very welcome to attend and support our event as individuals, the Norwich Labour Party banner is not welcome on the march. This would cause harm to members of the community."
It comes despite Norwich South MP Clive Lewis having made several public statements in support of the trans community and the Labour-led city council having previously passed motions of public support for LGBT+ groups.
The statement adds: "This has been a difficult decision and we acknowledge that the overwhelming majority of local members are active allies and will be disappointed.
"We also want to publicly thank Clive Lewis for his solid support for the whole LGBTQIA+ community, including recently on puberty blockers."
It comes after Mr Streeting, who became health secretary following the general election, revealed he would be backing recommendations made by Hilary Cass in a review, which urged restrictions to be placed on the use of puberty blockers.
He had previously said: "We will always put the safety of children first.
"Our approach will continue to be informed by Dr Cass's review, which found there was insufficient evidence to show puberty blockers were safe for under 18s."
In an interview with The Sun newspaper leading up to the election, Mr Streeting backtracked on previously saying he believed transmen are men and transwomen are women.
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