The Scottish Labour leader was speaking in Stirling as he launched a new bus urging voters to choose his party on the regional list ballot.
A recent poll put Labour in third place behind the Scottish Conservatives with 23 per cent of the constituency vote and 19 per cent of the regional vote, leaving the party with 24 seats to the Conservatives’ 28.
Asked whether he was concerned if not having a clear anti or pro-independence stance would lead to voters simply not turning out to vote for his party, Mr Sarwar said it was likely the SNP who were more worried.
He said: "I actually think that people most worried about the turnout challenge right now is probably going to be the SNP rather than us to be honest.
"They are projecting they are guaranteed to win, they are projecting they're going to get a majority, so that in itself comes with its own challenge.
"I think the Conservative campaign is purely focused on a core vote strategy. They just want to hold on to what they have got and that's why in some ways they are talking about the referendum and independence even more than the SNP are, because that's the way they are going to try to maximise their share of the vote.”
This election could come to down to how as few as 5,000 votes are cast in six constituencies with the narrowest majority for pro-union parties.
Edinburgh Southern, East Lothian and the narrowest majority in Scotland, Dumbarton, are all held by Scottish Labour.
Mr Sarwar said: "I am trying to reach out to people who are not just in the base of the Labour Party. I am trying to reach out beyond our base and that is reaching out to different demographics geographically, but also different demographics in terms of where they have stood on previous binary choices.
"I think that is a message that is cutting through, I think we are getting more and more activism on the streets.
"I think we are who will be the most active campaign in the final week, we will be the most energetic campaign in the final week.”
Asked why anyone voting SNP on the constituency list would vote Labour on the regional list, the Scottish Labour leader said it was a “mistake” to assume voters only sat in pro-union or pro-independence camps.
Mr Sarwar said: "I think it is too easy and I think the SNP make this mistake and I think the political bubble more widely makes this mistake is to assume that every single person falls into a category of they’re either a hardcore no voter who hasn’t got the ability to want to work together on issues that they agree on and everyone who is a Yes voter is a hardcore Yes voter who doesn’t want to work with anyone else on issues they agree on.
"I know from speaking to people there are people who still want to support independence at some point in the future but also want us to focus on recovery in the next parliament.”