Tram strikes are being flagged to start again next week, with the public transport union planning to bring the city's network to a halt as a pay dispute continues.

On the next two Thursdays, November 28 and December 5, about 1500 drivers and customer service personnel at Yarra Trams will down tools for four hours between 10am and 2pm.

Melbourne tam drivers on strike at the Malven tram depot earlier this year. Credit:Justin McManus

It follows two days of strike action taken by members of the Rail, Tram and Bus Union in late August.

The union is still demanding a 6 per cent annual pay rise over three years, while Yarra Trams has offered 3 per cent over four years.