The British National Party is likely to face a number of legal challenges relating to issues such as discrimination, employment law and even criminal offences, legal experts have said.

The party won two seats in the European elections last week, its biggest political success to date. Party leader Nick Griffin won one seat in the north-west region, while the other went to Andrew Brons for Yorkshire and the Humber. The BNP will now receive £4 million of public funding.

Speaking to the Guardian, Gavin Millar QC, a specialist in election and discrimination law said: “An unincorporated association like the BNP which has genuine screening for membership cannot unlawfully discriminate. There will inevitably now be legal challenges to this.”

Millar added: “A black or Jewish candidate who applied and didn’t get the job on grounds of their racial or religious background would have a claim in the employment tribunal.”

The BNP’s constitution currently states membership is “strictly defined within the terms of … ‘indigenous Caucasian’ and defined ethnic groups emanating from that race”.

Legal experts say that the party could be regarded as a members’ club. A recent Lords ruling said these do fall within anti-discrimination laws.

The receipt of public funds also makes the BNP open to employment law: “If an individual challenges and they maintain a practice not employing any visible minority people, there is no doubt that like any employer who has such practices, they can be sued,” said employment barrister Peter Herbert.

“When they are in receipt of public funds they will have to be an equal opportunities employer. To do otherwise would be incompatible with public office.”

Herbert continued: “I can see the equality commission mounting an inquiry into how the BNP operate now. The office of public standards could also inquire.”

Regarding the possibility of criminal convictions, he said: “Any policy which incites racial hatred will be liable. Twelve years after Stephen Lawrence this is a sad place to be.”

Griffin was forced to abandon a press conference outside the Houses of Parliament earlier today when he was pelted with eggs by protesters.

An angry crowd surrounded his car chanting “Off our streets, Nazi scum”.