WITH 100 days until the General Election the parties are preparing for what could be a watershed campaign in Scottish and Glasgow politics.

Labour currently hold the seven Westminster seats in Glasgow and have enjoyed a monopoly on city seats since 1987.

The majorities are sizeable, ranging from just under 4000 in Glasgow North to almost 16,000 in Glasgow North East, with six of the seven seats carrying a Labour majority of more than 10,000 votes.

Labour can usually expect backing from the city voters at a General Election as the direct opponents are seen as the Tories and not the SNP.

This time, in post referendum Scotland however, it could be different.

According to opinion polls the predicted swing from Labour to the SNP could see nationalists winning General Election seats in Glasgow for the first time.

Indeed Labour face their toughest challenge since the1970s, when the Tories were the serious competition.

Apart from 1983 when Roy Jenkins held Hillhead for the SDP after winning a by-election the previous year, the only Labour defeats in the last 40 years have come at by-elections.

Jim Sillars, won in Govan in 1988 and John Mason in Glasgow East in 2008 but both returned to Labour at the following General Election, Govan with a significantly reduced majority, Glasgow East, almost as big as before.

Labour's incumbent MPs are all standing again and the SNP is expected to announce its candidates in the next few weeks.

The SNP are looking to build on their Holyrood and referendum success in Glasgow and to use the army of new members out campaigning in communities.

They will look to make nuclear weapons on the Clyde a key issue.

The party will combine that with campaigning for an end to austerity and argue it will be far better to spend the billions of pounds earmarked for renewing the Trident weapons system on public funding instead.

Labour are looking to return as many Scottish MPs as possible to help Ed Miliband not only defeat he Conservatives but win a majority to become Prime Minister and avoid having to negotiate a coalition.

The will have to fight not just the Tories but persuade the voters Labour and not more SNP MPs is the best hope of kicking David Cameron out of Downing Street.

The Labour tactic is to argue both the Tories and SNP are bad for the finances of the country and ordinary families.

Cathy Jamieson, Ayrshire MP and shadow Treasury Spokeswoman said: "The Coalition will leave a legacy of raising tax on ordinary families while giving millionaires a huge tax cut.

"As the Institute for Fiscal Studies said last week, tax and benefit changes under this government have left households, on average, £1,127 a year worse off.

"Meanwhile, the SNP are actively looking to bin the Barnett formula, which would mean billions of pounds of spending cuts to public services.

"Whether it is the Tories or the SNP, both are offering Scotland false promises."

While the Labour faces may be more recognisable with experienced politicians who have held senior positions like Margaret Curran, Ian Davidson and Anas Sarwar, the SNP are expected to field several lesser known but up and coming candidates, but who were highly active during the referendum and have build up valuable grassroots campaigning experience.

The party's deputy leader, Stewart Hosie said: "A large number of SNP MSPs could be decisive in who holds power and not the LibDems.

He said: "Our message is that people have 100 more days to make Scotland's priorities Westminster's priorities - which can only be achieved by voting SNP.

"Scotland needs and wants an alternative to austerity cuts, cancellation of the horrendously expensive Trident renewal, the real powers of Home Rule, protection for our oil and gas industry, and safeguarding our place in Europe by ensuring that all four UK nations would have to vote for EU withdrawal before the UK could exit.

"These are objectives which the people of Scotland can achieve - and can only achieve - by voting for a strong team of SNP MPs to hold the balance of power at Westminster."

The Glasgow seats will be a two horse race between Labour and the SNP no matter how many candidates are on the ballot paper.

The Conservatives will be trying to hold their one Scottish seat and have no hope in Glasgow but will hope to retain and if possible grow their core vote in the city.

The Liberal Democrats, second in two Glasgow constituencies in 2010 will be looking to recover from the disaster of the Holyrood 2011 election, where they lost their sole city MSP.

They are again positioning themselves as the alternative to both Labour and Tories while looking to sideline the SNP as only interested in independence.

The Greens and Ukip are expected to field candidates in the city and can expect to pick up some votes in certain constituencies, which could be a determining factor if the final results are close.

The General Election is on Thursday May 7.