Sequels, for whatever reason, aren't as common in theatre as they are in the cinema. But Australian playwright David Williamson decided to revisit one of his earliest hits, Don's Party (1971) in a play both written and set four decades after the first.

Don Parties On, Rep's fourth production for the year, is being directed by Aarne Neeme.

''Often you fear a sequel is going to be a reprise of the earlier play. But it's different with this one and I've become a great advocate of it,'' Neeme says.

In the original Don's Party, Melbourne schoolteacher Don and his wife Kath invited their friends around to watch the results of the 1969 federal election. Most of them were Labor supporters who hoped the long period of Coalition government would end but as the night went on and it became clear this was not to be, other disappointments, recriminations and regrets flowed as freely as the beer.

Don Parties On is set at another party on the eve of the 2010 election and much has changed in the interim.

''Nobody drinks beer - they all drink wine - high-class red,'' Neeme says. But that's only the start of it.

''The characters are older and perhaps a little bit wiser.''

Kath (played by Judi Crane) is now a lecturer in art, her career having surpassed that of now retired Don (Peter Robinson). He has written an unsuccessful novel that upset his friends as its characters were based on them. Some of the old crowd have died or fallen by the wayside but a few turn up again.

Unsuccessful businessman Mal (Pat Gallagher) and state parliamentarian Jenny (Helen Vaughan-Roberts) are divorced but womanising, conservative lawyer Coolie (Len Power) has long been married to Greens supporter Helen (Liz St Clair Long).

''He's been corralled but doesn't know it.''

Don and Kath's son Richard (Sam Hannan-Morrow), a successful ad man, has recently left his wife Tracy for Roberta (Anne Mewburn-Gray), an artist, and brings his new paramour along to meet his parents.

Deeply unimpressed by her father's actions is his teenage daughter Belle (Isha Menon), who turns up with some unwelcome news.

''They intend to watch the election but a whole lot of issues from past and present intrude,'' Neeme says. ''There are tinges of antagonism and regret.''

He thinks Don Parties On is ''a terrific play''.

''There's a blend of real feeling as well as great humour. It's very rich in that regard.''

He thinks it will particularly resonate for the members of that generation - his generation - who, in the late 1960s and early 1970s were experiencing new freedoms and had a sense they were going to change the world and fix its problems. Williamson, of course, is also part of that cohort.

''I've known David for 40-odd years,'' Neeme says. ''I've done a lot of his work.''

Although Williamson is often thought of as a comedy writer - ''people tend to see him as a smart arse'' - Neeme thinks he is underrated and that there's often more to his plays than that. He compares Williamson to Alan Ayckbourn and Neil Simon: prolific, popular and somewhat pigeonholed playwrights whose work may be uneven but who are more than the stereotyped view people sometimes have of them.

''I think it's the tall-poppy syndrome,'' Neeme says.

With this production, he wanted to emphasise the ''tragicomic'' aspect rather than taking a broadly funny approach and he says Williamson was happy with that.

''I believe he's going to come down and see it.''

Don Parties On will be Neeme's 10th production in a 30-year association with the company. He made his Rep debut with Tom Stoppard's play Enter a Free Man in 1983.

''Peter Robinson was in that, too. We've come together again.''