‘Clare will be fishing in the same pool as us’

A double loss would be hugely embarrassing for Sinn Féin leader Mary Lou McDonald following a poor presidential election performance and a notable drop in the polls for the party.

Sinn Féin also faces trouble in the local elections as it has lost a significant number of councillors since 2014 thanks to tensions within the party.

Senior Sinn Féin sources expressed grave unease over the consequences of a Daly candidacy.

One said: ‘Clare will be fishing in the same pool as us. Be there three or four seats, she will represent a serious threat to our candidate.’

She has, the source said, ‘huge credibility with the anti-water charges lot’ as well as being an outspoken supporter of the Repeal the Eighth movement.

The source said: ‘We could end up fighting it out with the Greens or Fianna Fáil for the last seat.

One source said of Ms Boylan: ‘Lynn and her partner [Dublin TD] Eoin Ó Broin are Sinn Féin new royalty. No one would be very cheerful if Lynn’s seat was lost.’

Mr Wallace is not seen to be as formidable a political operator as Ms Daly, but Sinn Féin is uneasy that the seat of Ms Ní Riada could come under pressure.

senior Sinn Féin figure said: ‘Ní Riada is damaged goods; that presidential election has done her serious damage.’

It is believed Mr Wallace is anxious to run for Europe because of the stark decline in his Dáil constituency vote, which almost halved between 2011 and 2016. He would likely struggle in the European elections but does have a chance.

A Sinn Féin source said discontent with Ms McDonald’s leadership was rising: ‘Mary Lou has never exactly wowed the electorate, in Dublin Central or Europe. The Northern command are already unhappy. There will be serious questions asked if this goes wrong.’