WATCHING Prime Minister's Questions yesterday, there was a strong tax element - discussions about the financial transaction tax, the bank levy and benefits to SMEs.

David Cameron was, fairly enough, asking Ed Miliband what Labour's growth strategy involved. The prime minister launched into a list of this government's actions: the bank levy, the lower bank bonuses, the higher fees on non-doms and the agreements with Switzerland and Liechtenstein.

Hold on a minute, I thought. The Swiss agreement might have its seeds in the Labour government, but it is fair enough for the Conservatives (and lest we forget the LibDems) to claim credit.

But Liechtenstein? The Liechtenstein Disclosure Facility was brought into being in 2009 and signed by a Labour minister - Stephen Timms. This was not an initiative by this government.

Cameron's researchers have made a gaffe here, but it does highlight the success of the LDF. It has brought in the revenue and the next set of figures to be released - the first ones since the announcement of the Swiss deal - will be fascinating. It is likely to be the flood that follows the hitherto satisfying drip of disclosures.

Ownership of the LDF is highly desirable. Probably best for our prime minister not to steal it, however.