The National Party is directing its supporters to preference the Liberal Democrats, a pro-gun party which believes in fully legalising semi-automatic weapons and arming citizens to keep government power in check.

As voters prepare to go to the polls on Saturday, National Party MPs vying for re-election across the state will be handing out How-to-Vote cards which recommend preferencing the Liberal Democrats second in the NSW Legislative Council.

John Barilaro is among the National Party MPs whose How-to-Vote cards direct voters to put a "2" next to the Liberal Democrats.

It comes after Premier Gladys Berejiklian has repeatedly condemned Labor for brokering a preference swap with the Shooters, Fishers and Farmers Party, claiming the minor party "wants to give guns to 10-year-olds".

The Liberal Democrats, whose lead candidate for the upper house is former NSW Senator David Leyonhjelm, have a more extreme policy platform on guns than the Shooters party.