An aide of Nigel Farage is accused of carrying out work for Ukip on European parliamentary time

Nigel Farage, Paul Nuttall and six other Ukip MEPs could be told to pay back up to £500,000 after the European parliament launched an investigation into allegations that they misused EU funds.

Officials are looking into accusations that the eight MEPs broke rules which ban full-time European parliamentary assistants, who are paid from EU coffers, from working for a national party, according to reports.

Ukip has rejected the allegations, which the MEPs are responding to individually. Party sources also called into question the integrity of a man they claim is the key witness whose testimony started the inquiry.

Labour’s Seb Dance silently makes his point as Nigel Farage addresses MEPs in Brussels yesterday

Mr Farage and Ray Finch, another Ukip MEP, could be asked to repay almost £85,000 that was paid to their joint assistant Christopher Adams, according to reports.