Russia's government is to allocate Rb12.4 billion ($410 million) in public funding to the Irkut MS-21 programme this year.
The 2013 budget for the twinjet family has been disclosed by the Russian trade and industry ministry.
Trade minister Denis Manturov says the aircraft has secured 135 firm orders with overall commitments of 256.
Design documentation will be finalised this year, the ministry adds.
It states that the first flight of the MS-21-200 is scheduled to take place in June 2015 and maintains that it expects certification in 2017.
The ministry says the MS-21, which is intended to replace Tupolev Tu-154 and Tu-204 fleets, will use Russian components "to the maximum extent" and that documentation is being transferred to plants involved in the programme.
It will initially focus on two variants, the ministry states, the 150-seat -200 and the 181-seat -300. Irkut has previously discussed plans to include a larger -400 model, with over 200 seats.