More than £2m of public money has been paid to trade unions by the Welsh government, new figures show.
The details came to light following a written question by Welsh Conservatives’ deputy leader Paul Davies to finance minister Jane Hutt.
According to the figures, 15 trade unions received £2.4m from the Welsh government during a three-year period.
The Welsh government justified the payments by saying they were made to raise skill levels among workers.
But Mr Davies, AM for Preseli Pembrokeshire, expressed concern whether the Labour-led administration in the Assembly were using public funds to “feather its own nest”.
He highlighted a £1m donation to Unison and £87,000 given to GMB.
Mr Davies said the former had donated £3,065 to first minister Carwyn Jones’s leadership campaign in 2009 and the latter gave £14,197 to Peter Hain’s failed bid to become deputy prime minister two years previously.
He said: “Giving substantial sums of taxpayers’ money to party political donors serves only to undermine people’s trust in politicians and weaken their faith in Welsh Labour ministers to act in the national interest.”
The Welsh government hit back at Mr Davies’ accusations, stressing that trade unions played a vital role to Wales’ workforce.
A spokesman said: “These payments result from a long-standing commitment to work with key stakeholders in Wales to raise skill levels of the employed workforce.
“The trade union movement in Wales plays a vital role in this process by raising awareness and arranging flexible learning opportunities that meet the needs of employers and individuals alike.”