Did Alastair Darling take a mortgage from Northern Rock during its alleged reckless phase?

Private Eye asks these fascinating questions:

When did Chancellor Darling become a Northern Wresk mortgage customer? Darling made this surprise announcement as a declaration of interest when making an announcement about the government's support for the failed bank on 11 October.

"My wife and I own a small flat in London which is presently let," he disclosed. This decalration had been made in the 9 October internet version of the register of MP's interests. There had been no mention of any London flat in the 28 August internet register.

So was the Straw Man one of the many who took advantage of Northern Wreck's giveaway deals as part of the kamaikaze dash for market share during 2006 and 2007 which brought about the demise? When was the property first disclosed in the register? Was it before the crisis broke in early September? How much is the mortgage, what are the terms and when is it due to be repaid? PErhaps we should be told as it presumably forms part of the taxpayers' security?