Last month, the BBC said that it would sponsor three debates next year for the 2015 parliamentary election. The most inclusive of these four debates would feature the leaders of the Conservative, Labour, Liberal Democratic, and UKIP Parties. The Green Party would not be included, even though it has an elected member of the House of Commons.
In response, the Green Party has gathered 200,000 signatures asking that the Green Party leader be included, and many prominent politicians from the major parties have signed. See this story, which seems to suggest that the BBC may reconsider.