Lucknow: A lot depends on the mood swing of voters in Uttar Pradesh as even a small change in their mind can tilt the scale for or against a candidate or party, going by the poll data of recent years.

As the state is witnessing a razor sharp contest this time among SP-Congress combine, BJP and BSP, even minor changes in the vote share will translate into huge shifts in a number of seats to make or mar the electoral prospect of a party or alliance.

A cursory look at data of the Assembly and Lok Sabha elections in recent years shows that in 2007, BSP won just over 30 per cent of the votes, SP a little over 26 pc, BJP 17 per cent and Congress about 8.5 per cent.

But, five years later though SP garnered just three more percentage points, it translated into a windfall for the party whose tally in the 403-member UP Assembly shot up from 97 to best ever 224 to put the party filly in saddle with thumping majority.

BSP's vote share in 2012 fell by 4.5 percentage points compared to 2007, but the loss was immense in terms of seats as the party's tally nosedived from 206 to 80.

In 2009 Lok Sabha polls, BSP won 20 of the 80 seats in UP with a vote share of 27.42 per cent, Congress got 21 seats with vote share of 18.25 per cent, BJP bagged 10 seats with 17.5 per cent votes and SP pocketed 23 seats with 23.26 per cent votes.