Fianna Fáil leader Micheál Martin is to reshuffle some Seanad portfolios in the wake of the resignation of Senator Averil Power from the party.

Senator Ned O'Sullivan, currently transport, tourism and sport spokesperson, is to replace Ms Power in education. Fianna Fáil leader in the House Darragh O'Brien is expected to retain the finance portfolio.

The party's only female Oireachtas member, Senator Mary White, a Dáil candidate in the new Dublin-Rathdown constituency, is expected to remain spokesperson on enterprise, jobs and innovation, given her business background. She was involved in running a highly successful chocolate company for a number of years.

“Martin will be conscious of Ms Power’s political ghost in the Seanad and will want his Senators to ensure a strong profile for Fianna Fáil,’’ said a party source.

"He will be particularly concerned that the party appeals to liberal Ireland in the wake of the Yes vote in the marriage equality referendum.''

Ms Power, who claimed the party failed to launch a sufficiently strong canvass in support of the referendum, and was critical of Mr Martin’s leadership, is viewed as a strong Seanad performer. She is expected to be equally active as an Independent.

Her resignation reduced the party’s representation to 13 Senators in the 60-seat House.

Although long-serving Senator Jim Walsh resigned the Fianna Fáil whip, in opposition to the Family Relationship Bill and the marriage equality referendum, he is likely to support the party on other issues. It is also thought likely he will have the whip restored before the next Seanad election.

Mr O'Sullivan, from Listowel, Co Kerry, strongly supported Ms Power's views on social issues and publicly distanced himself from the harsh criticism of her by some former colleagues when she resigned from the party.

He said Ms Power had presented the party with challenges, while “adding to the diversity and urban appeal the party needs’’. He also said he supported here “progressive initiatives and admired her strong work rate’’.

Mr O'Sullivan is a supporter of Mr Martin's leadership and played an active role in the recent Carlow-Kilkenny byelection which was won by Fianna Fáil's Bobby Aylward.

His promotion to the education portfolio is viewed in Leinster House as recognition of ability and a desire by Mr Martin to replace Ms Power with somebody with a liberal social outlook.

Mr Martin knows he has political enemies within his own party in the Seanad.

Some of the long-serving Senators are still privately angry at his attempts to move them off the political pitch in the last Seanad election when he sought votes for younger candidates, including Ms Power, with potential to contest Dáil elections in the future.

Senators like Mr Walsh, who is an outspoken member of the party’s conservative wing, defied Mr Martin and retained their seats.

They remain embittered and a similar battle could take place in the next Seanad election if Fianna Fáil finds itself in opposition. That election will take place in the aftermath of the next general election later this year or early next year.