This is the full text of the statement released by Averil Power on Monday:

“Last weekend we witnessed politics at its finest.

In the marriage equality campaign, we saw what can be achieved when people dare to believe progress is possible and work together to make it happen.

We saw that bravery, vision and leadership can win people’s hearts and help deliver major social change.

And we saw that politics can make a real difference to people’s lives.

I’m not in politics for the sake of it.

I ran for election in 2011 because I wanted to make a difference.

I believed our country needed a strong opposition to hold the Government to account.

I wanted to champion issues I care about such as education and social justice.

And I thought Fianna Fáil would learn from its mistakes and work hard to rebuild the trust of the Irish people by showing it had changed for the better.

Over the past four years, I have tried hard to help deliver that change.

However, I have repeatedly been rebuffed by my own party.

When I called publicly for Bertie Ahern to be expelled from Fianna Fáil in 2011, I was reprimanded by the party leader. It would be another year before he was prepared to recommend that course of action.

The strategy I was asked to develop on improving female participation in the party has largely been ignored.

And I have become increasingly uncomfortable in a parliamentary party that is out of touch with the needs and concerns of ordinary people.

I stuck with it because, despite everything, I still believed I could help deliver change from within. I was encouraged by the support of like-minded members. And I thought things would improve over time.

They haven’t and I no longer believe they will.

The party’s cynical and cowardly approach to the marriage equality referendum was the last straw.

For me, a referendum on equality went to the core of what real republicanism should be about. Our members knew that when they voted for a motion calling for the party to support marriage equality at the 2012 Ard Fheis.

Despite this, the vast majority of the party’s public representatives refused to campaign for it. In fact, I was the only TD or Senator who did a proper canvass for the referendum in their constituency.

Some Fianna Fáil representatives declared publicly that they were voting No. Worse still, others told me they would be voting Yes but were afraid of campaigning for it in case they would lose votes.

Fianna Fáil’s overall approach to the referendum symbolized everything that is wrong with the party.

Fianna Fáil lacks vision, courage and leadership.

- It doesn’t know what it stands for and lacks credible policies on most major issues.

- It is afraid of taking clear positions in key debates for fear of losing support.

- And Micheál Martin has become a leader without any followers. His frontbench are all pulling in different directions and prioritising their personal political success over the needs of the party and the country.

Having lost my faith in Fianna Fáil, I cannot in good conscience knock on doors in Dublin Bay North and ask people to vote for the party. In my view, they are simply not fit for government.

I know I would have a strong chance of being elected for Fianna Fáil in the next election. But I have come to the conclusion that I don’t want to be a Fianna Fáil TD. I want to be true to myself and have the courage to walk away from the party.

I am therefore resigning from Fianna Fáil, effective immediately.

I am doing so with a heavy heart as I have many good friends in the party. I am also immensely grateful to everybody who has supported me over the last few years.

It was not an easy decision to make but I am convinced it is the right thing to do.

I intend to serve out my term in the Seanad as an Independent Senator.

I feel I have made a strong contribution there and would like to continue to do so.

The day my Adoption Information Bill passed the Seanad with unanimous support is one of the proudest days of my life. I was delighted to secure the support of the Seanad, and later the Dáil, for the motion I initiated calling for Ireland to formally recognise the State of Palestine. I have also enjoyed working with members of all parties and none on issues like education, health and mental health.

I look forward to continuing this work and also taking other initiatives to help address the struggles people are facing in their daily lives.

I have not made any decision yet about whether I will run in the Dáil election or not. I will discuss that with my supporters over the next few weeks.

Today’s decision was a big enough one for now. But I know I have done the right thing.”