The Liberal Democrats’ website struggled to cope with a surge in demand following Nick Clegg’s success in the televised leaders debate last week, according to Keynote Systems.

Keynote Systems, which measure internet performance and is monitoring the technical performance of key political parties’ websites in the run up to the general election, found that the Lib Dem website took on average 11.37 seconds to load on the morning of 16 April. The leaders’ debate was broadcast on the evening of 15 April.

The Lib Dem website also had a fall in availability following the debate, from an average 99.34 per cent during the week of 12 to 18 April, to 90 per cent. This means that 10 per cent of website visitors were not able to access the website at all on the morning of 16 April.

The Lib Dems’ website is already bottom of the table when it comes to website availability, with the Conservatives and Green Party coming joint first at 99.96 per cent. Labour’s website availability was 99.57 per cent.

However, the Lib Dem’s average weekly website performance was still second fastest (2.05 seconds), after the Green Party’s site (1.11 seconds). The Conservatives’ website averaged at 2.65 seconds, while Labour’s website was slowest, with a reaction time of 4.94 seconds.

Mike Bromilow, UK country manager for Keynote Systems, said: "With further televised debates scheduled for the coming weeks, the Conservatives, Liberal Democrats and Labour parties must ensure that their websites are optimised to cope with an influx in site traffic during and after the debates.

"Research has shown that site visitors become impatient when having to wait for longer than two seconds for a site to load – our findings show that in order to keep potential voters happy, there is significant work to be done by the three leading parties."