Nicola Sturgeon has vowed to make Scotland's voice heard and fight the Conservative's austerity plans after the SNP gained a record 56 seats in the Commons.

Scottish First Minister made the statement as she unveiled the newly-elected SNP MPs in Edinburgh and told them to "work with others" in Parliament to end austerity across the UK.

Sturgeon insisted that Scotland will no longer be "be "sidelined or ignored" at Westminster after the party achieved a landslide north of the border, claiming all but three constituencies.

"Let us be very clear – the people of Scotland voted for an SNP manifesto that had ending austerity as its number one priority and that is the priority for these men and women to now take to the very heart of the Westminster agenda," she said.

"We will continue to reach out to people of progressive opinion right across the UK so that we can put ending austerity, investing in public services like our precious NHS, investing in a stronger economy to get more young people in jobs… We will work with others to put those priorities right at the heart of Westminster."

Her comments follow Prime Minister David Cameron's promise to lead a "one-nation" Conservative government.

In a statement which seemed to acknowledge that his tough talk on further benefit cuts, and polarising attacks on the SNP during the elections had left him with work to do.

The Scottish First Minister had a brief conversation with David Cameron on Friday, agreeing to face-to-face talks "as soon as possible", according to Sky.

Speaking about the conversation, she said that Cameron had not indicated that he was prepared to offer Scotland full fiscal autonomy.

She told her audience in front of the Forth Bridge: "As I told the Prime Minister when I spoke to him yesterday, it simply cannot and will not be business as usual when it comes to Westminster's dealings with Scotland.

"Scotland this week spoke more clearly than ever before and my message to Westminster is that Scotland's voice will be heard there more loudly than it has ever been before.

"Our job is to repay the trust you have shown in us and I pledge today that that's exactly what we'll do.

"We will not let you down."

As Sinn Fein's four MPs refuse to vote in the House of Commons a left-of-centre alliance, including the SNP, Liberal Democrats and Labour, would require at least 32 Tory backbenchers to vote against the government or abstain, to succeed in any vote.

If Plaid Cymru, the Green Party and Northern Ireland's SDLP were to join that theoretical alliance, at least 25 Conservative MPs would have to rebel.