Just what is going on with our leading firms? Last week the Guardian reported that the big cheeses of the accountancy world - KPMG, PwC, Deloitte and Ernst & Young - were almost permanent fixtures in the corridors of power. Electoral Commission figures showed the firms had donated £1.9m in staff costs and consultancy to the three main political parties since May 2009.

Yet when Obiter searched for leading law firms with the same idea, they barely featured. Just nine of the top 100 UK firms, either through themselves or a subsidiary, declared giving time or money to political parties since 2003.

PI behemoth Irwin Mitchell was the biggest donor, giving £85,750 to the Labour Party between July 2003 and August 2009. Labour also benefited from cash donations from Bircham Dyson Bell (£3,620) and Brabners Chaffe Street (£14,000).

Intriguingly, DLA Piper appears to have had a change of political heart after the 2010 election. Previously, it had donated more than £25,000 to Labour over five years, but in December 2010 it was the Tories who cashed the cheque, to the tune of £7,957. And there is a salutary lesson for firms looking to dabble in politics: always back the winner. Poor Mishcon de Reya donated almost £15,000-worth of consultancy time to David Miliband’s failed campaign for the Labour leadership in 2010.

Yet even with these donations, the top 100 law firms contributed around a fifth of that of their accountancy brethren - and nothing like the same level of pro bono work.

Obiter suggests they stop worrying about trivialities like clients, service and profits and get down to Westminster: that pole won’t grease itself, you know.