Media playback is unsupported on your device Media caption Alasdair McDonnell said he was not ruling out the SDLP leaving the executive

SDLP leader Alasdair McDonnell has rejected the proposal of an electoral pact with Sinn Féin, saying his party's principles were "not for sale".

He told the SDLP conference his party would not dilute its values for a pact in next May's Westminster election.

Martin McGuinness, Sinn Féin, had called on the SDLP to establish pacts like those agreed by unionists.

On Saturday, he said the SDLP's refusal was "an ill-thought out, knee-jerk reaction".

Mr McGuinness said pro-agreement politicians should join together in the face of unionist pacts. He said the SDLP's refusal represented "a lost opportunity".

However, at the conference on the outskirts of Belfast on Saturday, Dr McDonnell said his party would stand candidates in every constituency in Northern Ireland.

"They won't be based on sectarian, selfish interests," he said.

"Don't think the SDLP will dilute our policies or our values in favour of a pact. The SDLP policies and principles and values aren't for sale."

Dr McDonnell also said he was not ruling out the SDLP leaving the Northern Ireland Executive.

"We will not be part of a broken and politically bankrupt executive if it doesn't get its act together," he said.

He said the SDLP reserved the right to "operate from a position of constructive opposition".

At the conference on Saturday, Mairía Cahill was a guest speaker.

The Belfast woman repeated allegations that she was raped by a suspected IRA member in 1997 and that republicans were involved in a cover-up.

Five people who were prosecuated as a result of her allegations were acquitted in court this year after after she withdrew her evidence.

Sinn Féin has insisted there has not been a cover up.

The conference got under way on Friday night with deputy leader Dolores Kelly repeating her support for the SDLP going into opposition.

She insisted that differences over whether to leave the executive were not a big policy fault line within the SDLP, but simply a difference over tactics.

Speaking on Friday evening, Dr McDonnell said he was confident that he would retain his South Belfast seat next May, even if he had to fight a single unionist candidate and Sinn Féin also contested the constituency.