Rachel Reeves and her expenses before she became an MP

The situation around Christmas gifts, which Reeves also bought for her PA and others, was more complicated.

That's because, according to internal bank guidance we have seen, these could be bought on expenses providing they were small gifts of £25 or less and they were not bought using the Motivation card.

The £25 limit was based on tax advice as anything more substantial would attract tax.

It appeared to her colleagues that Reeves had broken these rules.

But there does appear to have been confusion about the policy. We have also seen emails showing that Reeves was encouraged by her boss to buy more expensive Christmas presents, and to pay for them with her Motivation card.

In late October 2008, Reeves's manager wrote that "after checking with other departments, it looks like the standard practice of buying Christmas gifts for direct reports using motivation bank will continue this year", emails seen by the BBC show.

She suggested spending £50 to £75 per person on the presents.

A reminder titled "further clarity" about how to buy Christmas gifts and how much to spend was circulated by another HBOS employee in early December, emails show.

Reeves and the other managers who were later investigated were all among the recipients of this email confirming the rules on Christmas gifts.

While seasonal gifts, such as at Christmas, were allowed, the managers were explicitly told they could not use Motivation cards for these purchases. The cost of these "trivial" gifts was also not allowed to exceed £25, in line with HMRC guidance, the email said.

This is because rewards for performance at work are taxable whereas seasonal gifts such as those given for Christmas, providing they are not too costly, are exempt.

Replying to the email, Reeves wrote that she didn't understand why the "goal posts are shifting" and said she had already ordered and paid for her presents using "Motivation Bank/Thanks, and I do not intend to cancel them," claiming this would cost more time and money.

A colleague responsible for finance acknowledged that the message on paying for Christmas gifts hadn't always been clear but said: "I don't believe that the goalposts are being moved."

Receipts show that gifts bought by Reeves at Christmas 2008 included a £49 handbag for her PA, while she herself received £55 worth of wine from her boss.