Talks with other devolved leaders were held at Downing Street.
Clegg: Tories Don't Represent UK
Nick Clegg has warned Scottish voters the Conservatives have "basically mutated into an English party chasing Ukip votes in southern England".
The Liberal Democrat leader criticised the party he was in coalition with, arguing that David Cameron has "given up even pretending to seek a mandate as Prime Minister for the whole of the United Kingdom".
The Conservative leader has said he will try to form a government if his party wins just one more seat than Labour in tomorrow's General Election.
But with the Tories uncertain to see off the challenge of the SNP in the one Scottish constituency they won in 2010, SNP leader Nicola Sturgeon has insisted the next government must represent all of the UK and cannot "ignore" Scottish voices if it is to be considered legitimate.
As well as accusing the Conservatives of having effectively given up on Scotland, Mr Clegg hit out at Ms Sturgeon's party, claiming a large block of SNP MPs at Westminster would seek to use "every smidgeon of grievance that they can muster in the next parliament to mount the case for a second referendum".
Mr Clegg made the comments as he visited a nursery in Bearsden, outside Glasgow, with Scottish Lib Dem leader Willie Rennie.
With the race for No 10 being too close to call, Mr Clegg said: "I'm a campaigning politician, I'm not a soothsayer, I can't tell the future.
"All I know is with more Liberal Democrats MPs in Parliament there is the greater likelihood of having stability, decency and unity in the British government."
He insisted again he would not do any coalition deals that would rely on support from either the SNP or Nigel Farage's Ukip, saying: "One party wants to break up one union we believe in, the European Union, the other party wants to break up another union we believe in, the United Kingdom."
He said: "I can't be clearer - no pacts, no deals, no arrangements with either Ukip or the SNP."
Mr Clegg argued that voting for the Lib Dems is the ``best way'' to ensure the next government would be one for the whole of the UK, saying: "The Conservative Party is now not even pretending to be a party for the whole UK, the Conservative Party has basically mutated into an English party chasing Ukip votes in southern England.
"It has got barely any representation in Scotland and is behaving in this election campaign as something tantamount to an English Conservative Party.
"David Cameron, I think, has given up even pretending to seek a mandate as Prime Minister for the whole of the United Kingdom, yet 20% of the Liberal Democrat party is north of the border.
"We really care about what happens in Scotland and care about the integrity of the United Kingdom in a way that certainly the Conservatives don't any more."
He added: "Every vote for Liberal Democrat MPs across Scotland, those 11 MPs fighting against the SNP, is a vote for the integrity of the United Kingdom.''
The Liberal Democrat leader insisted that the SNP, which has enjoyed surging support since last year's independence referendum, was "on manoeuvres" and added: "Their mission remains as it always has been: to win a second referendum.
"They will use every smidgeon of grievance that they can muster in the next parliament to mount the case for a second referendum whilst sticking to a plan which would rack up mountains of debt which would fall on the shoulders of our children and grandchildren.
"I don't think that's fair on the children we've just seen at this nursery in Scotland, we should wipe the slate clean rather than burden them with more debt."
With tomorrow's vote apparently set to result in another hung parliament, Mr Clegg said he had become "increasingly perplexed by the habit of both David Cameron and Ed Miliband of not accepting they're not going to win", accusing the Conservative and Labour leaders of "perpetuating this pantomime myth that they're going to win a majority when they're not".
But as he headed for the north of Scotland on the final stretch of his battlebus tour of Britain, he said he had "absolutely relished" the election campaign.
Mr Clegg told reporters: "I genuinely find campaigns exhilarating at the best of times, this one in particular, because it's a rare opportunity for us to tell our side of the story without our story being clouded or misrepresented.
"I really enjoy it, and given how much our chances had been completely written off at the beginning of the campaign I think we will be the surprise story tomorrow night."
He continued: "Quite a long election campaign is something I relish, rather than fear, because the more time we have to tell our side of the story the better it is for Liberal Democrats, because it's a really, really good story, and it wasn't told enough for the last five years.
"I've absolutely relished every single minute of explaining with pride what Jo and myself and other Liberal Democrats have done for the country over the last five years, and what we want to do over the next five years.
"We're really proud of what we've done, we don't think we've got nearly enough credit for the things we've done, or indeed the many things we've stopped, so any opportunity to tell our side of the story is one we grab with both hands."
After five years in coalition Government with the Tories, he said: "I don't think we've had the fair share of the credit for the good things, we've had a pretty hefty share of the bad things.
"I have enjoyed being able to set the record straight a bit over the last six weeks on the campaign trail and I think people respond really well to that."
Stefano Brizzi is accused of murdering the Scottish police officer.
It happened in the Govanhill area at lunchtime.
It's being treated as attempted murder.
Most Viewed Pictures On Heart
Recently Played Tracks
To listen live, choose your preferred location:
Deposit £10 to get a £40 Welcome Bonus - That's £50 to play bingo, slots and more!*
Over 50 tracks to make you feel-good. New album out now...
Find your local four day weather report here.
Make Heart the soundtrack to your day and you could be a winner with great prizes up for grabs throughout the day.
Find out more about some of the companies advertising on Heart Scotland- East.