Speaking specifically about the election in Scotland, the prime minister warned that every vote for the SNP would "undermine" her Brexit negotiations and help Labour leader Jeremy Corbyn to become prime minister.
But Ms Sturgeon said the Tories should "watch their language", as she accused Labour of focusing on independence due to a lack of positive policies after former chancellor Alistair Darling called on the SNP to rule out a second independence referendum while campaigning in Edinburgh.
Her party has seen increased support among the voter base in Scotland, however, with a third of Scottish voters claiming they would back the Conservatives in the election, according to a Panelbase poll.
The party has struggled in Scotland ever since, winning only one MP at every Westminster election and remaining stuck in third place in the Scottish Parliament until a resurgence past year, led by Ms Davidson.
It is the first time the Yes side has been given a majority in public surveys since the weeks after the European Union referendum, when one put support at 53 per cent.
Ms Davidson replied: "Well I said on the big issues of the day in Scotland".
Asked by presenter Andrew Neil whether the General Election is about independence or not, Salmond yesterday said: "I've said exactly the same as Nicola Sturgeon on that".
This has been rebuffed by May's government and polls show that although support for independence stands at around 45 percent, most Scots do not want another vote on secession after rejecting it by a 10 point margin in 2014.
After targeting Labour heartlands in the North of England, Mrs May set her sights on tartan seats last held by the Tories up to 30 years ago.
"There are clear barriers to making your proposals a reality", Davis said in a photocopy of the letter dated March 29 and addressed to Michael Russell, the Scottish minister for United Kingdom negotiations on Scotland's place in Europe.
Meanwhile, candidates in all 650 parliamentary constituencies will be invited to sign the Armstrong's pledge prior to the election on June 8. Following the Prime Minister's outline for the kind of Brexit deal that she was seeking, a March 2017 poll conducted by Ipsos-MORI reported that 47% of Scottish voters said that they would vote yes to independence, while 53% said that they would vote no.
"That's why they're turning to the Scottish Conservatives, the only party serious about keeping Scotland part of a strong United Kingdom".
"In fact, most people in Scotland see the common sense in saying now is not the time for yet another divisive referendum campaign".
"A vote for the SNP will ensure there is a strong voice in Westminster to stand up for Scotland".