Nicola Sturgeon’s party almost swept the board in the 2015 general election, taking 56 of the 59 seats up for grabs north of the border.
But a surge in support for the Scottish Conservatives could make that success difficult to repeat.
Ruth Davidson, the Scottish Tory leader, has already said her party has a “pretty good” chance of winning Mr Robertson’s Moray seat on June 8, saying it will be a “titanic battle” there.
The Tories will also be looking to claim other high-profile scalps from the SNP, and a record result in the council elections could now see the party targeting Pete Wishart’s constituency of Perth and North Perthshire, and even Gordon, where former first minister Alex Salmond is the SNP candidate.
Mr Robertson launched his re-election campaign in Elgin and said: “’I know first-hand how important it is to have a strong voice to stand up for Scotland and to stand up to the Tories at Westminster.
“Now more than ever, that strong voice matters for the people of Moray, for the people of Scotland and for the people of the whole of the UK.”
He added: “Every vote for the SNP is a vote for a strong voice for Scotland to stop the Tories having a free hand to do whatever they want.
“With a strong group of SNP MPs elected on June 8 - Scotland’s voice will be heard at Westminster like never before.”
In this week’s local government elections the Tories increased the number of councillors they have in Moray from one to seven.
The SNP returned nine councillors for the area, two fewer than in 2012. Labour also has one representative on the authority, and there are eight independent councillors.
Mr Robertson claimed: “The Tories want to take Moray for granted and use local votes to deliver their damaging hard line agenda, putting thousands of jobs at risk, just as they want to block opposition elsewhere in the country.
“I will always put the people of Moray and the people of Scotland first.
“As an MP I have stood up for the thousands of defence jobs in this constituency against Tory cuts, for local businesses against the Tory threat to take us out the single market, and for our rural economy when the Tories have repeatedly let down our fishing and farming industries - and I will fight for the best deal for Moray and for Scotland at every opportunity.”