image captionSir Keir Starmer handled – and inspected – several rolls of wallpaper

The Conservatives have criticised Sir Keir Starmer for visiting a John Lewis store to make a dig at the PM over the Downing Street redecoration row.

Tory chair Amanda Milling said the Labour leader was “playing politics” by posing with rolls of wallpaper in a branch in Greater Manchester.

The funding of recent Downing Street flat renovations is being investigated.

Sir Keir has urged Boris Johnson to reveal “quickly” who initially paid the bill for the work.

But the prime minister said he would cooperate with the investigations, but added: “I don’t think there is anything to see here or worry about.”

Questions over the funding of the Downing Street flat refurbishment – overseen by Mr Johnson’s fiancée Carrie Symonds and reported to have cost up to £200,000 – have dominated the headlines for several days.

The Electoral Commission is investigating, as are the UK’s top civil servant and the prime minister’s own standards adviser.

Ms Symonds has denied reports that she objected to the way the flat had been decorated by her fiancé’s predecessor, Theresa May – which society magazine Tatler claimed a visitor had once called a “John Lewis furniture nightmare”.

On a trip to a London school, Mr Johnson joked that this was “the one thing I object to in this whole farrago of nonsense”, adding: “I love John Lewis.”

But during a campaign visit to Greater Manchester ahead of next week’s local and mayoral elections, Sir Keir popped in to the chain’s Trafford Centre store.

He made for the furnishing, fabrics and cushions department, on the first floor, and inspected the wooden wallpaper racks.

Sir Keir read the “wallpaper calculator” and picked up some of the rolls – patterned and plain – at one point smiling to a photographer.

media captionBoris Johnson: What we are doing is focusing on the stuff that really matters.

This appeared to anger Ms Milling, who tweeted one of the pictures, writing: “When we say Labour are playing political games this is exactly what we mean.

“Today the PM visited a school to see how we are levelling-up opportunity, focusing on people’s priorities. Keir Starmer is doing exactly what we said he’d do – playing politics.”

Earlier, Labour’s deputy leader Angela Rayner called Mr Johnson’s stance “disgusting”, adding that the “general public need to know” about the flat payments.

Prime ministers get £30,000 towards refurbishing their Downing Street accommodation, such as the recent work carried out for Mr Johnson and Ms Symonds by designer Lulu Lyttle – whose company says its aim is to contribute to the “joyful atmosphere of any interior”.

Mr Johnson has said he paid the costs himself, but he has not specified whether this happened when he first received the bill, or whether he was loaned the money and later repaid it.

media captionLabours Angela Rayner says the prime minister needed to tell people where the money came from.

The Electoral Commission – which oversees political finances – will investigate the Conservative Party’s compliance with laws on political donations, having said there are “reasonable grounds to suspect that an offence or offences may have occurred”.

Sir Keir said the situation was becoming “farcical”, adding that “it would take [Mr Johnson] about one minute” to give the details of who paid for the works, and when, “and then he can get back on with the day job”.

But Mr Johnson insisted he was “focusing on the stuff that really matters”, including “priorities”, such as easing Covid restrictions and improving the economy.

The prime minister’s own newly appointed standards adviser, Lord Geidt, is also investigating the funding of the flat redecoration.

Cabinet Secretary Simon Case, the UK’s most senior civil servant, is carrying out a review, at Mr Johnson’s request.

And the BBC understands that Labour MPs have asked the Parliamentary Commissioner for Standards to look into the issues raised and whether any rules been broken.

The prime minister’s flat is actually above 11 Downing Street, rather than No 10, because it offers more space.