Brighton and Hove Green Party councillor Ben Duncan has apologised for his tweet which he facetiously said he only smoked cannabis when "murdering, raping and looting".

The comments were made during an online discussion about proposals to open legal cannabis cafes in Brighton on Duncan's blog.

Green has since apologised for discussing rape in a light-hearted way.

The comment prompted two senior Labour councillors - Green leader Gill Mitchell and the party's community safety spokesman Warren Morgan - to call for his resignation.

Mitchell said: "This is the latest in a series of irresponsible comments from a senior Green councillor. Ben Duncan should think about the wider effect of his statements. For him to make light of the serious crime of rape in this way is plain wrong."

Duncan, who stood as the Green Party's candidate in Brighton Kemptown in the 2010 general election, said: "I apologise unreservedly for mentioning rape in what was meant to be a light-hearted, ironic tweet.

"I understand that this may have caused distress and I'm sorry.

"On the topic of my blog about cannabis cafés the wording is clear that I was not calling for 'coffee shops' to open in Brighton but was simply joining the current debate about drug decriminalisation by satirically asking whether Brighton is as liberal as Amsterdam used to be.

"I'm sorry if anyone misunderstood my intention."

Council leader Bill Randall agreed the comments were "undoubtedly in bad taste" but was pleased that Duncan apologised. He said calls for Duncan to resign may have been opportunistic.

"Rape simply is not a joking matter even when the joke is intended to be ironic or satirical," he said.

"But opposition councillors who've called for his removal are being opportunistic.

"Ben has done a great deal of good work as a councillor, particularly for the neighbourhoods and communities of Brighton and Hove, and it is wrong to take advantage of his momentary lapse of judgment."