'Out of the ten smallest seats, 9 are held by Labour and 1 by the Liberal Democrats. The largest seats tend to be Conservative ? places like Daventry (88,758), Northampton South (89,722) and Banbury (87,168). Leaving aside the Isle of Wight, out of the 10 largest English seats, 7 are Conservative, 3 are Lib Dem. At the last election, the fact that the boundaries were 14 years out of date benefitted Labour to the tune of 10 seats, costing the Conservatives around 8 seats and the Lib Dems around 2 seats.'
'Wales however continues to enjoy over-representation at Westminister ? using England?s electoral quota they would have 32 seats, but thanks to the lower electoral quota in Wales they currently have 40 seats. Since Wales contains large numbers of Labour strongholds, this benefits Labour. How many seats Labour would lose if Wales only had 32 seats would depend on the exact boundaries, but it would probably be about 5
UK Polling Report Election Guide.