The Baird government will begin the National Disability Insurance Scheme a year ahead of schedule, starting in Penrith and the Blue Mountains in July, Premier Mike Baird will announce on Sunday.

Children aged under 18 in the Penrith and Blue Mountains area will be included in the scheme this year, after the Abbott government agreed to bring forward funding.

The Liberal Party will officially launch its election campaign at a function in the central business district on Sunday.

Mr Baird will tell supporters that NSW was the first state to sign up to the NDIS, and it is a reform he is “passionate about because of the impact it will have on the lives of people with a disability”.