Bristol East MP Kerry McCarthy complains on her blog that Green Party leader Caroline Lucas MEP was invited to speak at the Labour conference fringe meeting.
Fortunately, not everyone in the Labour Party has such a closed mind, and Caroline was warmly received at meetings yesterday of the Fabian Society and the progressive group 'Compass'.
It's not unusual for politicians to 'guest' at other parties' conferences. For me, one of the most memorable fringe meetings at the Green Party conference was addressed by Labour's Alan Simpson MP, when he spoke powerfully and convincingly about the virtues of the Tobin Tax.
It's not just the left and the Greens that support such a tax. In the last few weeks it's been backed by Adair Turner, who heads the Financial Services Authority, and by French President Nicolas Sarkozy.
None of us seem likely to persuade the Labour/Tory establishment though, who clearly favour 'the treatment as before' - the banking system awash with money, along with savage cuts in public spending.