More than 1 million self-funded retirees will be given extended relief on their superannuation savings, and pensioners could be included in a one-off, $250 bonus scheme to assist with the cost of living, as the Morrison government seeks to shore up the grey vote in next week’s federal budget.

The budget, to be used as a springboard for a federal election to be called shortly after, will extend for another 12 months the halving of the superannuation drawdown rate for self-funded retirees.