Following on from a landmark year for LGBT equality in the US, a storm of anti-LGBT legislation is expected in the coming year.

A report by the Human Rights Campaign released on Friday suggests that anti-LGBT legislation is expected in 27 states.

The report notes that in the past year, 151 anti-LGBT bills were filed across as many as 33 states.

It goes on to note, however, that many failed to pass.

The HRC also notes that bills still pending will carry over into 2016 legislative sessions.

Some states, including Indiana, Missouri, South Carolina and Tennessee have also had new anti-LGBT legislation introduced.

“2016 will prove a critical year for the fight for LGBT equality in states across the country,” HRC President Chad Griffin said in a statement.

“The progress our movement has made is threatened by an organised effort to pass discriminatory legislation that seeks to rollback our hard-won rights. We will have much work to do to defend our rights this year, but we will not waiver in our fight to expand the map for LGBT equality to every corner of this country.”

The HRC also points out that some states do not have legislative sessions lined up for 2016, notably Texas, Montana, Nevada and North Dakota.

Texas has over 20 anti-LGBT bills pending from 2015.

However 46 states and the District of Columbia will convene.

Three categories are named by the HRC for the bills, including anti-transgender, religious refusal and municipal pre-emption.

The HRC also notes that some legislatures have pro-equality legislation pending.