May 6: the day that could see the Labour Party leaving the power after 13 years. Current PM Gordon Brown competes for a new mandate against a more energetic David Cameron (Tory Party) and the fresh Nick Clegg (LibDem). Who's got the biggest chance to be invited by the Queen to form the Government? Director of LSE London Tony Travers makes a brief description of the tree main candidates for No. 10.

The rules of the political scene will constraint politicians to sort out the situations among them, so that the Queen's choice would be as clean as possible. The queen will consult herself with her private secretary. Her secretary can also speak to constitutional law lawyers and experts. "Only in the most complicated, messy scenario the decision will fall on the Palace", Tony Travers says.

What has kept the LibDem Part away from power for so long it the British electoral system - it's first past the post in each constituency. Only the winners get a seat, regardless whether someone coming second in a different constituency had been voted by a larger number of people. Plus, people will not vote for you if they think you are not going to win, even if they like and they wish you would win (tactical vote). And the core Labour voters are superior in number to the core LibDem voters, Travers adds.

Gordon Brown

Gordon Brown's main strong point is the "economic leadership", especially with the prospect of a growing public debt on the background. There is of a domino effect, with the problem originating in EU countries such Greece. And here, the Labour Party, with Gordon Brown and Alistair Darling ahead, can raise points, LSE London director believes.

One thing you must do in a campaign is to carry on with the race, believing you could win. Otherwise you'll stop, Travers says, explaining the rush of the Labour Party to leave Gordon Brown's last week's political gaffe behind. The British PM, getting in his car after a meeting with the public, forgot his microphone on and described one Labour voter who challenged him over immigration "bigoted". According to the LSE expert, if the Labour party comes third in the popular vote, it will be traumatic for the party after 13 years in power.

David Cameron

"The conservatives have to face the problem if their big idea, which they cannot sell on the doorsteps", Travers claims. He refers to Tory's idea of "the big society" or "the big state", "a perfectly traditional conservative idea". Another issue Travers underlines is the fact that the LibDems have imposed themselves as the agents of change, despite similar aspirations of the conservatives, who have spent several years building on that.

Additionally, although they are constantly the first in the polls, they record five or six percentages less than they did in constant years. If invited by the Queen to form a Government, David Cameron could call the LibDems to form a coalition. But the British electorate is not used with coalitions and sees this form of government as "unBritish".

Nick Clegg

LibDems are in a somewhat awkward situation in relationships with both Labour and Tory. Nick Clegg never denied the possibility of forming a coalition with any of the two parties. But Travers says that when Nick Clegg talks about this issue, "he sounds evasive, just like another politician, which is not good for his 'we are different' attitude". Even if the LibDems want to radically change the voting system, Tony Travers believes they aren't very different from the Tory party or Labour Party, and the liberal-democrat politicians proposed for key roles "cannot be used as the agents of change".

"A conservative majority party would put an end to the LibDem dream", Travers says. There is this possibility of having good elections, but getting power, not getting influence, because of the electoral system, Travers believes.

On the economy's situation, the Institute of Fiscal Studies from Great Britain has recently accused all three parties for failing to come with solid proposals for the reduction of the budget deficit, the LSE London directors says.

As for immigration, the issue has been on the people's mind during the campaign. According to Travers, David Cameron tried to push it in the beginning of the debates and Brown's gaffe has given it an actual shape one week before the elections.

"The way in which the British show their level of fed-upness with the current politicians is to move their preferences not to the extreme, but to the centre. (...) And because of the British electoral system, it is very likely to vote for 'Revolution' (by British standards) or for 'no change' by mistake. Because when you've got nearly 30-30-30% for all parties, it is almost impossible to use your vote efficiently", Tony Travers concluded.