Hillary Clinton has hit out at rival Bernie Sanders – after he accused LGBT rights leaders of colluding with the “establishment” by backing her.

The Human Rights Campaign (HRC) board of 32 LGBT rights leaders  voted unanimously in favour of Hillary Clinton for President – noting her raft of LGBT policy pledges.

HRC opted to favour Clinton’s plan – which includes 24 sweeping pledges across LGBT policy areas – over Sanders, who has outlined just seven specific LGBT policies.

But the Sanders campaign suggested the endorsement “cannot possibly be based on the facts” because he has been a lifelong supporter of LGBT rights – and accused HRC of being an “establishment organizations voting for the establishment candidate”.

However, Hillary Clinton fired back today – questioning the Senator’s claim that HRC and reproductive rights group Planned Parenthood are both part of the “establishment” for backing Hillary.

She tweeted: “Really Senator Sanders? How can you say that groups like @PPact and @HRC are part of the “establishment” you’re taking on?”

HRC insisted: “There are certainly several friends of equality in this race, but the 32 community leaders who comprise HRC’s Board of Directors have unanimously decided that Hillary Clinton is the champion we need to fight for us each day on the campaign trail and every day in the White House.

“She has a strong record, a strong agenda, and a strong ability to win against any Republican running on an anti-LGBT platform in November and lead from Day One.”

The former Secretary of State has come under scrutiny for only backing same-sex marriage in 2013 – though Bernie Sanders also did not officially back same-sex marriage until 2009.

None of the 12 Republican candidates provided HRC with details of any policies to benefit LGBT people.