THE controversy surrounding MP Michelle Thomson is a warning for the SNP.

It is said that parties don’t win elections incumbents lose them.

It is when support for a party falls or disappears that its opponents get their opportunity, and it can be a drip effect.

Take the Tories in the 1990s under John Major lurching from one scandal to another following on from the end of the Thatcher period.

The people eventually had enough.

Waiting in the wings was New Labour, fresh faced, squeaky clean Tony Blair and his team of able capable men and women armed with integrity and principles.

Then that fell apart and people had enough, paving the way for David Cameron.

In Scotland, Labour were rumbled a lot earlier and it was the SNP that benefited.

Following two Holyrood successes it reached a high point this year as the party capitalised on the optimism many felt following the referendum and from the disillusionment with Westminster and the new MPs carry a heavy burden of expectation and responsibility.

The success did not come overnight but was the culmination of years of hard work by high profile politicians like Alex Salmond, Nicola Sturgeon and many others as well as the long days put in by party activists up and down the country.

That respect can be destroyed far quicker than it takes to build up and that is what the party must guard against.

If any of the MPs is found to be another greedy, out for themselves money grabbing opportunist on the make it will undo years of hard work of others.

The focus so far has been on whether Michelle Thomson broke the law and that is for the Police, prosecutors and courts to determine, no-one else.

But the nature of the business deals that are under investigation do not fit snugly with the image the SNP promoted during the election and referendum.

Values of fairness, social justice, equality and honesty were espoused by candidates and campaigners at every election meeting and in interviews throughout the election.

If people think Michelle Thomson profited from property deals which involved capitalising on the insecurity and vulnerability of people to make a fast buck she may find the public less than forgiving.

To take advantage of people in desperate need to sell in order to get their home at a knock down price then sell it on quickly for a huge profit would be seen by many as unscrupulous at best and downright grasping and greedy at worst.

If that is the case I doubt many of her colleagues in the SNP will have sympathy either.