After Scotland voted to stay in the United Kingdom in last year's referendum, the main British political parties must have thought their job was done. Surely now the Scottish National Party, with its whole raison d'être rejected, would wither away in time for the forthcoming general election? Instead SNP membership has increased from 25,000 to more than 100,000. The SNP now looks set to win anything from 40 to 54 of a possible 59 seats in the election; a huge increase from its present tally of six MPs. How did the British parties let this happen?

Most of the blame must be levelled at the conduct of the Scottish Labour Party during the referendum campaign. While the SNP was offering stirring speeches and a vision of a more socially just Scotland, Labour focused like a laser on the perceived risks of independence. Dire warnings followed of higher food prices, economic depression and even higher chances of terrorist attacks if Scotland became independent. This may have been enough to make people reconsider independence but it's hardly any way to treat your base.

Additionally, the decision of Labour to join forces with the politically toxic Conservatives in order to campaign against independence now appears a disastrous decision. "Red Tories" is how many Scots now describe Labour politicians for daring to side with the Conservatives, who have been hated since Thatcher's wave of privatisations and job cuts in the 1980s. Overtures from Labour to its Glasgow heartlands have been rejected since the referendum and the party now finds itself likely to be reduced to a rump in a country it has dominated for decades.

Another recruiting agent for the SNP has been Prime Minister David Cameron. When the referendum result was announced, the Conservative leader could have travelled to Scotland, made an assurance he would deliver further autonomy and attempt to heal the divisions created by a bitterly fought campaign. Instead, from the steps of 10 Downing Street he announced that his previous promise of further devolution of powers to Scotland would now come only if accompanied by greater powers for English MPs at Westminster that would controversially mean MPs from Scotland, Wales and Northern Ireland could be excluded from certain stages of the legislative process.

The Liberal Democrats, who entered into coalition with the Conservatives five years ago, are also likely to lose out to the SNP surge in support. After going into the previous election with a pledge to abolish student tuition fees, the Lib Dems instead chose to vote for the tripling of fees upon entering government. Although this applied only to students in England, to progressive Scots it is symbolic of the party's drift away from the centre-left since becoming a coalition partner with the Conservatives. One of the Lib Dems fighting to save their seat is Danny Alexander, who has served as deputy to Chancellor of the Exchequer George Osborne for the past five years and is having to defend the government's austerity policies to his Highland constituents.