There are dangers and opportunities inherent in this. To begin with the dangers, the most obvious potential pitfall is for it to be little more than a Socialist Aliance Mark II, a reborn alliance of existing (and, with the exception of the SWP, very small) left organisations. Any left alternative needs to reach way beyond this, into the campaigns and movements that revolutionary socialists continue to operate in. It may be regarded by some as unfortunate that the letter makes no explicit reference to these movements and its achievements - the Gaza demonstrations, student occupations for Palestine etc - and the published letter has no accompanying pictures of these events, lending it a somewhat abstract feel.
Another possible danger is that any conference - as proposed in the letter - will be only a talking shop and produce little. This is linked to the possibility of it being perceived as a top-down affair, originating from a centralised call-out rather than emerging from real grassroots initiatives. The really vital thing is that local initiatives are encouraged and supported, with some kind of framework to support and strengthen them.
It should also be noted that shared anti-fascism is a weak political basis for any new left-wing formation. The BNP's success may be an immediate trigger for action, but we'll have to go beyond this quickly and look at what positive alternatives we can champion. There's also, of course, the ever-present threat of lapsing into sectarianism. This is something the SWP is likely to avoid, though the dismissive line about the Greens (in the open letter) is a little unfortunate.
The opportunities, meanwhile, are demonstrated by the successes for radical left candidates in a number of European countries recently: France, Portugal, Germany, Ireland etc. The conditions faced here are no different to elsewhere in Europe. It is also vital to recognise that the apaprent rightwards lurch represented by the election results is quite misleading. The Tories, UKIP and BNP saw little or no rise in their votes.
Many leftwingers have worked well together in campaigns, networks and movements. A process of political radicalisation, stretching back to the first stirrings of anti-capitalism in the early noughties, provides the backdrop to everything we do. Though economic struggle is still weak, there are at least some green shoots - Visteon, today's Right to Work conference - and Mark Serwotka and Bob Crow have signalled their enthusiam for the unions standing or supporting independent left candidates.
It's all to play for...