TWO key border marginal constituencies are almost certain to have a big influence on the outcome of the General Election.

If Huw Edwards can successfully defend his wafer thin majority of 384 in Monmouth then Tony Blair will surely be back in Number 10.

This traditional Conservative seat was won by Labour in 1997, but is near the top of the Tories' "must win" list.

Challenging Mr Edwards for the Conservatives is David Davies - one of the most prominent Tory politicians in Wales.

If the election is as close as expected then the number of votes picked up by Phil Hobson for the Liberal Democrats, Jonathan Clark of Plaid Cymru and John Bufton for the UK Independence party could make all the difference.

Brecon and Radnorshire is also a constituency the political anoraks will be watching closely.

It is one of the few true three party marginal seats having returned Liberal Democrat, Conservative and Labour MPs in the past 30 years.

The Conservative Andrew Davies will have to overturn the 750 majority of sitting Liberal Democrat Roger Williams if Michael Howard's party is to make any progress.

Brecon and Radnorshire, the largest constituency in Wales, is very rural and may seem an unpromising prospect for Labour's Leighton Veale. However, it was solid Labour between 1945 and 1979 when there were significant boundary changes.

The votes for Liz Phillips for the UK Independence party and Mabon ap Gwynfor of Plaid Cymru could make a difference.

Once again, tactical voting could be decisive in Brecon and Radnorshire.