Reserve Bank governor Glenn Stevens has admitted that the surprise $8.8 billion grant received from Federal Treasurer Joe Hockey was a figure suggested by the central bank.

The Abbott government handed a one-off $8.8 billion grant to the RBA in October so the bank could strengthen the reserve fund it uses to back up its foreign currency operations.

The decision reversed that of former treasurer Wayne Swan who, in an attempt to prop up the federal budget, took out a dividend from the bank against its wishes in 2012-13.

It also replenished the central bank’s reserve fund which had dwindled from $6.2 billion in 2009-10, to just $2.5 billion in 2012-13.

But Treasurer Hockey has been criticised by the Federal Opposition for the size of the grant.