In a pamphlet published by the Centre Forum thinktank this week, Liberal Democrat MP for Bristol West Steven Williams suggested the move could be one way of defusing public hostility towards the financial sector.
"There is a general feeling in this country that we need to get something positive in return for the bailout," he commented. "There is a danger that when the banks return to the private sector, it is business as usual."
Mr Williams - who is also the co-chair of the Lib Dem parliamentary Treasury committee - insisted that the initiative would not prevent the government from clawing back the Â£66 billion ($107.5 billion) on bailing the two banks out.
In January, the Financial Times cited unnamed sources close to RBS as being confident that the group would be returned to private hands early in 2012.
By Asim Shah