Purchases dating back to 2016 have come amid government funding cuts, with new ways of funding frontline services required.
Now, the authorities could increase the fund available for commercial ventures from £75million to £125million per council, after an independent report argued the current pots were ‘small’ and increasing them could help spread risk.
A councils spokesman said: “In Adur our investment gives us a net annual income of £809,500 a year and in Worthing the figure is £868,300 a year. This is money that goes to essential services, the demand for which continues to grow.
“We are being prudent in our investments, and have put measures in place to manage the exposure of risk to the councils.”
According to a joint governance committee report, Adur District Council owns Highdown House, an office block in Durrington, a service station petrol station and Morrisons in Cosham, an office in Uxbridge and a Waitrose in Altrincham.
Worthing Borough Council owns retail units in Montague Street, let to Burton and Dorothy Perkins, Bon Marche, Clarks, Brighthouse and River Island. It lets the Union Place car park to NCP, while it has offices in Fareham, Abingdon and Reading.
Labour councillor Beccy Cooper, leader of the opposition in Worthing, said her party was concerned about raising money for essential services by ‘taking risks’ but said the Government’s austerity measures left the councils underfunded.
The matter will next be discussed by senior councillors.
The future of Bon Marche, one of the councils’ investments, has been thrown into doubt after a takeover by retail billionaire Philip Day. Read more about it here: Bonmarché takeover puts jobs and stores under threat