Tony and Cherie Blair were advised by senior officials to pay back thousands of pounds they received in discounts on designer clothing to avoid public scrutiny while he was prime minister, newly released documents reveal.

Just as questions were raised over donations of designer attire to Keir Starmer and his wife, Victoria, No 10 suffered headaches over the Blairs’ wardrobe.

Officials were concerned about “public perception” if details of the Blairs’ discounts – of up to 60% from designers including Nicole Farhi – became known. The deals were arranged by Carole Caplin, a controversial fitness adviser to Blair and style adviser to his wife.

Over a period from July 2001 to November 2002, the couple benefited from £46,000 of discounts on clothing, which would have retailed at £76,000, but for which they paid about £30,000.

Files released at the National Archives on Tuesday show the then No 10 private secretary, Clare Sumner, wrote to Tony Blair in February 2003 stating Caplin had said most of Cherie’s clothes were “bought at wholesale price”, which translated into “basically a 60% discount”.

“For you [Blair] Nicole Farhi is at wholesale price (60% discount) and Paul Smith is a 25%. In terms of public perception the amounts involved are quite large.

“From July 2001 to December 2002 you and Cherie bought clothes from Nicole Farhi at a cost of £8,021.50. The retail price would have been £20,855. So that gives a benefit of £12,834, more than the total amount you actually spent.

“In addition, from July 2001 to November 2002, for Cherie from the credit card statements she bought £21,746.50 of clothes wholesale from James Lakeland, Paul Smith, Paddy Campbell, Tanner Krolle and Janet Thurston and from Barbara Bui at a 30% discount, that would have cost £55,149.23 retail, if Carole’s figures are correct. That is a discount of £33,404, more than was spent.”

Blair could argue Caplin was paid a salary, and any “discount” should be calculated after deducting that. The couple could also argue that other people with public profiles had similar arrangements. While a 10-15% discount might be defended, “it is more difficult to make the case for general discounts of 30% to 60%”, Sumner said.

While not arguing that anything had been done wrong – “indeed nothing has been” – Sumner said paying back in full “would mean nothing to declare in the Register, or publish in the gifts list”.

After discussions with the then cabinet secretary, Sir Andrew Turnbull, Blair was advised to write cheques for his clothing of £1,116 to Paul Smith and £6,532 to Nicole Farhi. “This provides you with the protection of the cabinet secretary. Nothing is put in the public domain, and we have a firm position to take with the press if this ever comes up,” Sumner wrote in April 2003. “Obviously the downside is the amount of money to be paid back and we would need to take care that this did not generate a story in itself.”

While it was agreed Cherie Blair, a high-profile barrister, did not receive any “preferential or beneficial treatment” in her role as prime minister’s wife, she was advised to divide her purchases into two on a 50/50 basis “part spouse of the PM, part career woman” and pay in full on the “public” half. She should also require designers to sign confidentiality agreements to ensure there was no incentive for them to provide goods cheaply in order to exploit the fact that the prime minister’s wife wore their clothes, it was advised.

Sumner added: “Cherie is happy about what we propose for her, but does not agree with our advice in relation to you and will talk to you separately.”

In 1999 Cherie was reported to have complained in private to friends that she was having to fork out tens of thousands of pounds from her own pocket when she accompanied the prime minister on overseas tours.

A spokesperson for Blair said there was nothing to add to what has already been disclosed which shows that advice was sought and followed. A spokesperson for Cherie Blair said: “Mrs Blair has nothing further to add to what is already on the public record. Advice was sought and followed at the time.”