This weekend marks one hundred days since the General Election. Even from this viewpoint, I’m not sure whether that means it was a recent event, or a fading point in ancient history.

But at the very least, this milestone gives those of us involved in that historic victory an opportunity to look back at our achievement and the great progress we’ve made since.

At the beginning of the year few believed that the Scottish National Party would win more than two dozen seats, a result that would have eclipsed the party’s best-ever result in a Westminster election. The day before the poll, a public relations company in Edinburgh carried out a survey of Scotland’s political journalists and found that despite the overwhelming polling evidence, few thought that the SNP would gain more than 40 to 45 seats.

Winning 56 parliamentary seats while breaking a range of electoral records exceeded all expectations both within and outwith the SNP itself. While this week’s astonishing opinion polls may suggest that support for our party may not yet even have peaked, it has precipitated a total realignment in Scottish politics. This includes the significant accomplishment that the SNP have now assumed the official status of the third largest party in the House of Commons. Scottish Members of Parliament now speak from the frontbench in every parliamentary debate, take part in every question session for Government ministers and actively participate in every parliamentary committee.

While some London commentators may talk as if Scotland has never had a group of MPs in the House of Commons before, it is certainly true that there has not been a group quite like this one.

Never has Scotland nor Scotland’s interests been so prominent in the business of the Westminster Parliament.

But it’s one thing to have potential and another to have real influence or power. That is why it is important to consider the impact of the 56 SNP MPs on UK politics over the last three months. Not only have we made our own mark in changing the culture and tone of business in the House, achieved through revolutionary acts such as actually turning up to listen and contribute to parliamentary debates, but the SNP Group at Westminster has already achieved some real political successes in a range of different areas.

While the SNP argued that a vote for us would help exert a different type of influence throughout the election campaign, it is already very clear that the slim majority the Conservatives now hold in the House of Commons is extremely vulnerable when critics of the Government work together.

Under pressure from the SNP, David Cameron’s Government has already shelved plans to run the unneeded referendum on the UK’s membership of the European Union on the same day as next year’s Holyrood elections; dropped proposals to abolish the Human Rights Act; and abandoned plans to repeal fox-hunting legislation in England and Wales, not to mention the unravelling of the ill thought-out proposals to stop MPs from Scotland voting on issues which help set the Scottish Government’s budget.

Most would agree that Parliamentary democracy flourishes where there is a strong opposition to hold the Government to account. In this Parliament it is clear that it is the SNP who are leading the opposition to the Tories. Labour’s continued lack of principle, demonstrated by their voting, or not, as the case may be, added to their absence of leadership, has left them floundering over the last three months, and in years gone by would have given the government of the day a free rein. No matter which candidate wins their forthcoming leadership election, the party as it currently stands seems doomed to turn inwards on itself, rather than staying focused on the needs of the country at large.

The SNP’s Group at Westminster, on the other hand remains united and focused on the task at hand. We’re from a diverse range of backgrounds and political traditions, but we’re committed to supporting each other and working together to further Scotland’s interests. Divided parties can’t provide an alternative to government and quickly lose the confidence of voters, as the Labour Party are now discovering.

There are still plenty of battles to be fought over Scotland’s interests in the remainder of this Parliament, and this Conservative Government still has the potential to cause further and fundamental damage to Scotland and our society.

On a range of issues from welfare reform, changes to the tax credits system and the devolution of promised powers for the Scottish Parliament, only an energetic, united, focused opposition will protect people in Scotland from the worst excesses and neglect of the Tories.

If the last 100 days has shown us anything, it is that Scotland finally has a strong voice at Westminster which is committed, first and foremost, to protecting our country’s interests. We’ll need to draw on all our strength and commitment if we’re to continue to make progress over the months and years ahead. We intend to do so.