Alliance Party leader Naomi Long with deputy leader Stephen Farry at the party's manifesto launch at the Park Avenue Hotel in east Belfast

The Alliance leader was commenting after head of communications Scott Jamison was discovered to have issued directives urging supporters to call the programme – without revealing their political allegiances.

The Facebook messages were posted ahead of Mrs Long’s appearance on the programme as part of the Radio Ulster series of Assembly election interviews.

Using a closed members-only site on the social media platform, Mr Jamison encouraged grass roots supporters to field “tricky” questions for political rivals, but to call in with “softballs” while Mrs Long was on air.

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As well as passing on the programme’s contact details, one message said: “We could do with some callers/tweeters/texters. It doesn’t have to be ‘why are you so amazing?’ questions, but by the same token, some ‘softballs’ wouldn’t go amiss.”

The message added: “Just remember not to identify yourself as Alliance or an Alliance supporter.”

Mrs Long told the News Letter that the message was a “tongue-in-cheek reference to our inability to fill audience places” for broadcasts during the last election, but “like any private conversation doesn’t read the same out of that context”.

Asked if she was aware of the Facebook message ahead of the radio interview, she said: “No, I wasn’t.”

Alliance Party Leader Naomi Long during her party's Election 2017 Manifesto Launch at the Park Avenue Hotel on Tuesday. Photo: Colm Lenaghan/Pacemaker Press

A party spokesman described the ‘Alliance Activists’ group as an “informal, private forum” and added: “Encouraging, not instructing, party members and supporters, who are members of the public themselves, to call in to public phone-ins is standard practice in all political parties. The selection of questions is down to the host and listening to the show, it is clear few Alliance calls were taken.

“We would be surprised if every other party does not have a similar outlet, where conversations of an equally candid and tongue-in-cheek manner take place. We would, however, be surprised if all were as tame.”

A spokeswoman for the BBC said: “Our radio phone-in programmes regularly attract a high volume of callers who want to ask questions or share their views live on air.

“In line with our guidelines, our production teams do their best to assess each caller to ensure they contribute to a fair and balanced discussion which our presenters chair live.”

Alliance Party Leader Naomi Long during her party's Election 2017 Manifesto Launch at the Park Avenue Hotel on Tuesday. Photo: Colm Lenaghan/Pacemaker Press

BBC editorial guidelines for the NI Assembly elections warn producers to “be alert to organised campaigns or lobbying by parties, pressure groups, candidates or people acting on their behalf, particularly on social media platforms,” and go on to say: “If organised lobbying is suspected during the election period, contributors may be asked to provide contact details for verification purposes.”