I have been writing about the possibilities of the Social Democrats becoming a greater force in Irish politics on at least 2-3 occasions in the last 6 months. Today’s further gains in support, on the back of an upward trend seen since the last election suggest this may well be materialising.

Having hit double figures twice with support at 10% in two polls since September 2025, the party has punched through again this month to secure 12% in today’s poll, a further gain of +2%, and in doing so secures its highest level of support ever in the Business Post Polling.

This high is on the back of a relatively consistent upward trend in support seen over the past 6-9 months, initially triggered by a good response from campaigning at the Presidential election and followed by very successful by-election results in May.

This no longer looks like a temporary bounce for one party while another party has a bad poll, but rather is starting to perhaps reflect a broader movement among voters looking for an alternative to the established parties.

The upward trend in support for the Social Democrats is in marked contrast to the downward trend in support for Fianna Fáil.  While still behind the three traditionally larger parties, they now sit just two percentage points behind Fianna Fáil on 14%, with Fine Gael on 18% and Sinn Féin leading on 21%.

Not so long ago the idea that the Social Democrats could be within touching distance of Fianna Fáil would have seemed fanciful. Today it looks entirely plausible.

At the same time, and in stark contrast to their success, their centre left colleagues in Labour look becalmed at 4% support.

The obvious question is where that support is coming from? Some of it is coming from previously undecided voters making a choice, but our polling suggests the Social Democrats are making perhaps their biggest gains among people who voted Sinn Féin in the past.

Among those who supported Sinn Féin at the last General Election but no longer intend to do so, almost a quarter now say they would vote Social Democrat. That suggests the party has become a real destination for progressive voters who remain dissatisfied with the Government but are no longer convinced by Sinn Féin.

It also helps to explain why Sinn Féin’s overall support has softened while the Social Democrats continue to climb.

The Social Democrats now secure an impressive 25% support among voters aged 18 to 24, making them one of the strongest parties among younger adults. Across all voters under 35 they stand at 20%.

Equally encouraging for the party is that their support is beginning to broaden beyond younger voters. Support among those aged 55+ has risen quite sharply over the last six months, hitting double digits at 11% in the most recent poll; while support among those in the middle 35-54 age groups is also climbing.

While their strongest performances remain among younger age groups, they are now recording meaningful support across almost every demographic, suggesting the party is establishing itself as a permanent, rather than temporary feature of Irish politics.

This initial strength in support among younger voters, which then transfers to older age groups, is very similar to the trend in support for Sinn Féin when it saw a groundswell in support following the 2020 General Elections.

For Sinn Féin, these numbers suggest the party is no longer losing voters primarily to apathy or indecision. Instead, it appears to be losing many of them to another party competing for those voters looking for an alternative to the establishment.

For Fianna Fáil, the picture may be even more uncomfortable.

Not only has support continued to decline, but the gap to the rapidly rising Social Democrats is narrowing with every poll. A party that once routinely secured over one in five first-preference votes now finds itself looking over its shoulder at a party that only a few years ago was considered a relatively minor force.

If these trends continue, the contest at the next General Election may no longer simply be about which of the traditional three parties finishes first.  It may also be about whether the Social Democrats can overtake Fianna Fáil to become the third-largest party in Irish politics.

That would represent one of the most significant realignments in Irish politics in a generation. But there is a long way to go for that to materialise.

At the same time, when a party rises steadily over successive polls, converts that support into bye-election victories, and begins attracting large numbers of former supporters from the largest opposition party, it becomes increasingly difficult to dismiss the trend as temporary.

The Social Democrats are no longer simply a small party having an occasional good poll, they are becoming one of the defining stories of the current political landscape.

Read the Business Post RED C Opinion Poll Report here