To mark 100 days of the first Conservative government in nearly 20 years, HuffPost UK is running 100 Days of Dave, a special series of blog posts from grassroots campaigners to government ministers, single parents to first-year students, reflecting on what's worked and what hasn't, whilst looking for solutions to the problems we still face.
This year's General Election may have returned David Cameron to Number 10 with a majority Tory government, but it was certainly not with the support of voters in Scotland - where the SNP won an unprecedented 56 out of 59 seats in Scotland and picked up 50% of the vote.
People placed their trust in the SNP to stand up for Scotland and to work with others to deliver more progressive politics - both in Scotland and across the UK.
And with a hugely increased Westminster SNP group, we have an unprecedented opportunity to build links and promote understanding in England, Wales and Ireland, both north and south.
There is a real appetite across the home nations to learn more about the significant political changes happening in Scotland. There is also tremendous goodwill towards the SNP and First Minister Nicola Sturgeon.
The SNP has much to say at Westminster which is relevant to our friends and neighbours in the other home nations and the English regions, including our opposition to austerity, promotion of better transport links and sustainable economic growth. As the effective opposition in the House of Commons, our progressive policy agenda is relevant to stakeholders and communities across Britain and Ireland.
And as David Cameron marks 100 days of his new government, he can reflect on the fact that the SNP has already forced him to back down or U-turn on a number of issues.
The government has been forced to rethink the scrapping of the Human Rights Act.
The possibility that the EU referendum could have been held on the same day as the Scottish Parliament election has been halted.
The proposal of English Votes for English Laws has gone back to the drawing board, instead of being imposed before the summer recess.
And, of course, we stopped the fox hunting ban being relaxed south of the border - which brought us widespread praise and gratitude from animal rights activists across the UK.
But on other issues, the first 100 days have failed to deliver.
Before the independence referendum last year, promises were made for substantial new powers to be devolved to the Scottish Parliament, but these are not being delivered by David Cameron's government - so a key task for the SNP in the months ahead will be to hold him to account and ensure that Scotland is given the job-creating powers it badly needs.
Then of course there are the Tories' vindictive welfare cuts. If Labour had voted with the SNP against George Osborne's assault on those on low incomes, then the Tories could have been beaten - instead they sat on their hands.
Some of these issues are of particular interest to Scotland, some to England and Wales, and some are UK-wide issues - this reflects the breadth of our approach and commitment to pursuing progressive politics.
Where we can build positive alliances we will do so - for example where 27 Tory MPs rebelled and voted with us on scrapping purdah rules before the EU referendum.
This will come back to the Commons again after the recess, at which point we will do everything we can to help build a united opposition.
And an extremely serious matter that must be addressed by the government is the one I recently raised at Prime Minister's Questions - the appalling need for women who have had a third child as a result of rape to have to prove this to the DWP in order to qualify for tax credits.
SNP MPs are working hard to be the leading opposition force to David Cameron's government at Westminster, and as long as Scotland remains part of the Westminster system, we will be the allies of people and politicians of progressive opinion - from whatever quarter - to shake up and reform it.Suggest a correction