Bernie Sanders (Alex Wong/Getty) and Joe Biden (Frederick M. Brown/Getty)

Bernie Sanders has launched a scathing attack on his Democratic rival Joe Biden’s track record of voting on LGBT+ rights issues.

Sanders is going on the offensive against Biden in an effort to secure his party’s nomination to fight Donald Trump for the presidency later this year.

In a number of recent speeches, he has hit out at the former vice-president over his support of policies such as ‘Don’t Ask, Don’t Tell’ and the Defense of Marriage Act (DOMA).

Bernie Sanders criticised Joe Biden for his past votes on LGBT+ issues.

“The point here is not just to look back 20 years ago, not just to look at consistency, it is to look at which candidate had the guts to cast difficult votes because they were the right votes,” Sanders said at a news conference last week, the Washington Post reports.

“All I can tell you is, whether it was Iraq, whether it was DOMA, whether it was ‘Don’t Ask Don’t Tell’, those were difficult votes. I was there, on the right side of history, and my friend Joe Biden was not.”

Joe Biden’s national press secretary has accused Sanders of lying, claiming Biden “voted to strike anti-gay language from the 1993 defence authorisation bill”.

All I can tell you is, whether it was Iraq, whether it was DOMA, whether it was ‘Don’t Ask Don’t Tell’, those were difficult votes. I was there, on the right side of history, and my friend Joe Biden was not.

Supporters of Biden note that he backed and voted for an amendment in 1993 to remove the ‘Don’t Ask, Don’t Tell’ policy from a broader bill.

Sanders and Biden are fighting for LGBT+ votes.

However, Biden did vote in favour of the Defence of Marriage Act – which prohibited federal recognition of same-sex marriage – while Sanders voted against.

Gaining the support of LGBT+ voters could be decisive for Sanders and Biden’s campaigns as both fight to gain the Democratic nomination for the presidency.

Sanders will hope to galvanise support among an already substantial support-base in the LGBT+ community. An NBC News exit poll released in the aftermath of Super Tuesday showed that 42 per cent of LGBT+ voters supported Sanders, while Biden won just 19 per cent of LGBT+ Democrats’ votes.

The poll also found that one in 10 of all Democrat voters on Super Tuesday identified as LGBT+, indicating that the queer community is a large one that will play an important part in who gains the party’s nomination.

Biden has since released an LGBT+ action plan in an attempt to galvanise support in the queer community.