The Green Party is grappling with how to manage its social media following a controversial post by its leader.

The Green Party of England and Wales is reviewing its social media operation which has been central to its surge in popularity over the past year, sources have told the BBC. They insist it is not connected to the backlash to Zack Polanski this week after he re-posted a photo of a man wearing a t-shirt with an image of a guillotine and the slogan "we're only making plans for Nigel" - seen as being a reference to Nigel Farage. But that incident has raised questions about whether it is sustainable for the Green Party leader to manage his own social media channels, with one party figure calling it an "avoidable mistake" and that Polanski "should have said sorry" for it. In an interview with BBC Newsnight, Polanski repeatedly refused to apologise for "an inadvertent mistake" but acknowledged he needed to "be better on social media". "I just didn't look carefully enough and I accepted it, as soon as I was aware of what happened I unaccepted it and took it down," he said. Like other high profile figures on social media, Polanski receives a lot of material from other users seeking re-posts. But unlike most political leaders in the UK, he still manages his own accounts, rather than handing control to party staffers. This may allow him to appear spontaneous and authentic - both valuable commodities on social media - but it comes with risks. The current row began after Polanski shared a single post on Instagram that contained a carousel of 20 pictures.