What are the criteria for registered political parties in the United Kingdom?

While Britain First has been repeatedly denied electoral registration despite being an active political organisation, having to go to the courts to challenge the Electoral Commission, the Electoral Commission has no qualms in having the British National Party as a registered political party despite repeated irregularities regarding the way those in charge of the British National Party are actually managing the organisation.

The situation has been so serious that auditors have often refused to give their assent when they have audited the accounts of the British National Party. 

Reported irregularites have had to do with the way monies donated presumably to the organisation have ended up being spent. This includes party membership feeds, legacies made to the organisation, management of expenses making monies pocketed by private individuals being registered as expenses for the purpose of tax avoidance.

Individuals linked to the organisation have even accused of signing applications for public grants under false pretenses and of using monies collected by organisation for the organisation to pay for private mortgages. 

Despite repeated attempts to launch an investigation into the ways whatever is left of the British National Party is actually run, years have passed and the organisation is suspected of being used by two private individuals as a cash-cow without any serious political commitment. A website continues to hosted, but of recent those in charge of maintaining the website walked away after they stopped being paid. Despite efforts made by a Labour Party MP to raise the issue with the Electoral Commission and the talk of a Police investigation, nothing was actually done. This raise the issue of the role the Electoral Commission is playing in the whole affair, on the one hand putting obstacles to registration of new political parties and on the other ignoring serious accusations of wrongdoing involving the British National Party.