TV election debates: DUP discusses complaint with BBC in Belfast
DUP leader Peter Robinson has said BBC bosses have not strengthened their "threadbare argument" for excluding his party from TV election debates.
He was speaking after senior DUP figures met the BBC's director of news and current affairs to discuss his party's appeal against its exclusion.
James Harding said he remained hopeful that the debates would be broadcast as planned in April.
The DUP has threatened to seek a judicial review of the decision.
Speaking after the meeting in Belfast, Mr Harding said there were still a few stages to go before the dispute might reach the courts.
He defended the BBC against the accusation that it was treating people in Northern Ireland as second-class citizens.
Mr Robinson said he had not heard anything that was new from Mr Harding and BBC Northern Ireland Director Peter Johnston at the meeting on Thursday.
The DUP leader said his party would await the outcome of its appeal to the BBC Trust, the corporation's arms-length regulator.
He said the appeal, expected to be heard next month, would provide the BBC and other broadcasters with an opportunity to change their position before the matter goes to court.
DUP deputy leader Nigel Dodds said a lot of activity was taking place behind the scenes, and a number of parties at Westminster were unhappy with the planned seven-party format.
The DUP had written to the BBC and ITV asking for an explanation as to why the party had not been invited to take part in the live televised election debates.
In his written reply to the DUP, BBC Director General Lord Hall is understood to have said the decision not to include them complied with the BBC's obligations of impartiality.
The BBC and ITV are currently planning to hold two debates involving the Conservatives, Labour, Liberal Democrats, UKIP, Plaid Cymru, the SNP and the Greens.
The DUP is currently the fourth largest party in the Commons, with eight MPs.
A third debate - hosted by Sky and Channel 4 - would feature a head-to-head between Prime Minister David Cameron and Labour leader Ed Miliband.