David's accommodating girlfriend Lisa (Lynch) books them an all-expenses paid romantic break to Venice. He responds with the announcement that he's having an affair and wants out of the relationship.

Writer-director Col Spector's debut feature tramples through the minefield that is metropolitan love: the male running scared of any sort of permanent romance and the female reluctantly conceding marriage is not just round the corner.

Mangan - a subtle comedy player with the look of Rufus Sewell's scarier brother - skillfully fleshes out David, carefully bestowing a certain empathy on a character that could quite easily become thoroughly dislikeable.

He leaves his nice girlfriend of three years in the lurch when he opts to run off with a flighty piece. Unfortunately, she's so flighty that she's embarked on an affair with a married man before David's had the chance to tell he's on he market again.

Stranded between two relationships - one broken the other purely theoretical - he follows a course of pitiful and ultimately unsuccessful wooing to get Lisa back and then embarks on the laddish singleton round of parties and pubs.

Spector's witty script is particularly strong on the awkward and inevitably clichéd dialogue of unravelling relationships and the performances excruciatingly convey the doomed air of affairs gone sour.

It's a reality check on the cosy world of Richard Curtis and - thanks to Mangan - a rather more believable sequence of events where the commitment-phobe discovers being young and single doesn't necessarily mean you're free.

One of the most rewarding scenes - featuring Mangan upsetting his hostess at a party by chatting up her hippy-drippy sister - is actually lifted from an earlier Spector short - New Year's Eve - which also featured a fleeting appearance by Keira Knightley.

She's moved on to rather bigger things. So too, you suspect. might Spector.

Tim Evans