"HE'S spineless," says the SNP's Toni Giugliano of his Liberal Democrat nemesis Alex Cole-Hamilton. "He'll do and say anything to get elected."

Welcome to Edinburgh Western, home of the fiercest and most combative election fight in Scotland.

The SNP took the diverse constituency, which takes in Edinburgh Airport, affluent villages, prestigious businesses and deprived Muirhouse, in its landslide of 2011. But LibDem strategists insist they can win back their former stronghold, and have allocated resources accordingly. "We're targeting it heavily and causing the SNP real problems," says one senior party source. "It's bad tempered, but that's because Toni's under pressure - it's really tight."

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LibDems point to an increase in votes for the party in the corresponding constituency at the general election, when the SNP candidate, a certain Michelle Thomson, did just enough take the Westminster seat.

They have focused relentlessly on the Thomson saga, with the MP forced to stand down from the SNP amid a police investigation into property dealings that looked, at best, morally dubious. The tactic has enraged Giugliano, who works for a mental health charity and is a former caseworker for the respected ex-MSP, Dr Ian McKee.

"His leaflets are all about the SNP and people who aren't standing," Giugliano fumes. "There's no positive message. I'm the candidate on the ballot paper, I'm asking people to make a judgement on me. All they want to talk about is a different candidate, in a different parliament, in a different election. Their spin is that people don't have an MP, which is just wrong."

He accused Cole-Hamilton, who also tops the LibDem list in the Lothians, of being "two-faced" over the SNP's controversial named person legislation, saying he had loudly backed it in his role with a children's charity before voicing concerns at recent hustings.

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"It's an absolute nonsense," Giugliano, who defeated incumbent MSP Colin Keir in an internal SNP selection fight to become the candidate, adds. "He's pleasant when we see each other, but he's running an incredibly negative and divisive campaign."

Giugliano, who remains the strong bookmakers' favourite with Cole-Hamilton priced at 5/1 and Labour and Tories candidates rank outsiders, insists he would rather focus on his pledge to become a mental health champion at Holyrood, saying he, like his mentor McKee, would not shy away from holding the executive to account regardless of party affiliation.

But the LibDems are unapologetic. They insist Cole-Hamilton has offered positive messages but that it is legitimate to point out that an SNP candidate, standing than 12 months ago, became embroiled in a scandal that remains unresolved and led to the area being represented by a politician with her credibility and influence in tatters.

Cole-Hamilton says he has knocked on 25,000 doors since last May, and dismisses Giugliano's claim that Thomson is a non-issue on the doorstep. In turn, he says that the SNP been "playing politics" over recent closures of PFI schools in the capital, attempting to blame the LibDems for faulty contracts in an attack that he claims lacks credibility.

He says that he has "no meaningful contact" with Giugliano, claiming the SNP candidate had long-since blocked him on Twitter, despite the rivals' campaign offices being just a few doors apart in Corstorphine.

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"If you deign to criticise the SNP you're pounced upon by nationalists, they just don't like it," Cole-Hamilton, who is set to welcome Tim Farron to the constituency and believes a victory could prove a national springboard for a wider LibDem recovery, says. "But it's incumbent upon me to point out that this area has been very badly served by the SNP in terms of both MPs and MSPs. People deserve better and I would see my role primarily as a servant to the community and delivering on what matters to them.

"They're desperate for me to stop talking about Michelle Thomson, but last year the SNP asked people in Edinburgh West to vote for someone they hadn't heard of and look what happened."

2011 result

Colin Keir, SNP, 11,965

Margaret Smith, Liberal Democrat, 9,276

Lesley Hinds, Labour, 7,164

Gordon Lindhurst, Conservative, 5,047

2016 candidates

Sandy Batho, Conservative

Alex Cole-Hamilton, Liberal Democrats

Toni Giugliano, SNP

Cat Headley, Labour