The d’Hondt system explained

The European elections will be contested using the d’Hondt system, named after a Belgian lawyer who devised it in the 1870s. In contrast to other forms of proportional representation the d’Hondt system allocates seats individually rather than as a simple proportion of the overall vote.

“The basic idea is that a party’s vote total is divided by a certain figure which increases as it wins more seats,” says Dr Sydney Elliott, senior lecturer in politics at Queen’s University, Belfast. “As the divisor becomes bigger, the party’s total in succeeding rounds gets smaller, allowing parties with lower initial totals to win seats.”

The party with the highest vote gets one seat allotted in the first round. Its vote is then divided by two. The party with the highest vote in the second round then wins a seat and its vote is divided by two.

If a party which has already won a seat wins another round then its percentage vote is divided by the number of seats it has won plus one.

This continues until all the seats are allocated.

Example: How the BNP could win an MEP in the North West (which will return eight MEPs) with just 8.5% of the vote (bold indicates winning party in each round)

Round Con Lab Lib Dem UKIP BNP Greens Oths
1 32.00 26.00 16.50 7.50 8.50 6.50 3.00
2 32.00 26.00 16.50 7.50 8.50 6.50 3.00
3 32.00 26.00 16.50 7.50 8.50 6.50 3.00
4 16.00 13.00 8.25 7.50 8.50 6.50 3.00
5 10.70 13.00 8.25 7.50 8.50 6.50 3.00
6 10.70 8.60 8.25 7.50 8.50 6.50 3.00
7 8.00 8.60 8.25 7.50 8.50 6.50 3.00
8 8.00 6.50 8.25 7.50 8.50 6.50 3.00