FROM SKY NEWS
The dossier was submitted during an unsuccessful legal challenge to the merger
Liberal Democrat deputy leader Vince Cable has tabled a parliamentary question asking if the document still exists, and if its contents can now be revealed.
The Treasury dossier was submitted in evidence during the unsuccessful legal challenge in December and January by opponents of the merger.
The Merger Action Group fighting the decision to waive competition law to allow the merger to go through took its case to a two-day hearing in London, but lost.
MAG spokesman Malcolm Fraser
The secret dossier was clearly central to the Government's case for riding roughshod over competition law.
It believes the Treasury document, which was not made public, sets out why Gordon Brown and Chancellor Alistair Darling thought the takeover was the only option.
The group also believes that copies of the document have been destroyed.
MP Vince Cable
Mr Cable's parliamentary question asks if the original still exists, and if so, whether Mr Darling will now reveal its contents.
He said: "There appears to be a lot of murky dealings surrounding the Lloyds TSB takeover of HBOS, involving the Government and the Lloyds board.
"It is important, both for taxpayers and shareholders, that we have more transparency about what actually went on when the takeover was being pushed through by the Government."
Mr Cable's question also asks what advice was given to Business Secretary Lord Mandelson by the Financial Services Authority about the merger and what alternatives his department considered.
MAG spokesman Malcolm Fraser said: "The secret dossier was clearly central to the Government's case for riding roughshod over competition law.
"Now that the takeover has gone through and the extent of HBOS's financial losses are now known publicly, why should the contents of the dossier remain secret?
"If it is no longer in existence, why not? What is the Government hiding?"
A Department for Business, Enterprise and Regulatory Reform spokesman said: "We've kept all the records that informed the Secretary of State's decision."