LONDON, May 28 (Reuters) - Senior British lawmakers have questioned fast-fashion giant Shein's suitability for a London stock market listing and called for greater scrutiny of the Chinese-founded firm.

Shein is stepping up preparations for a London listing after its attempt to float in New York faced regulatory hurdles and pushback from U.S. lawmakers.

The firm, known for its $10 tops and $5 biker shorts, faced criticism from U.S. lawmakers over alleged labour malpractices, lawsuits from competitors, and use of an import tax exemption.

British Finance Minister Jeremy Hunt held talks with Shein's Executive Chairman Donald Tang in February and the firm is keen to list in London, a UK government source told Reuters.

Britain is keen to attract more listings after losing out on some big-name flotations to other financial centres.

However, Alicia Kearns, the Conservative chair of parliament's foreign affairs committee, said Shein should not be permitted to list in London.

"With Shein's prices so low the London Stock Exchange needs to ask itself, whose suffering is subsiding those prices," she said in comments first reported by The Guardian newspaper.

"A company which has failed to make full disclosures about its supply chains as required by UK law, and where there are grave concerns about its factory working conditions has no place in London."

A spokesperson for Shein said: "SHEIN is investing millions of pounds in strengthening governance and compliance across our supply chain."

"Our regular supplier audits are showing a consistent improvement in performance and compliance by our supplier partners. This includes improvements in ensuring that workers are compensated fairly for what they do."

Shein's Modern Slavery Statement is available on its UK website as required by law, the spokesperson added.

Liam Byrne, the Labour chair of the business and trade committee, expressed concern that parliament's dissolution for a July 4 general election meant Shein's initial public offering might not get the necessary scrutiny.

"It is not ideal that Shein's floating in London could get the green light without parliamentary scrutiny," he said.

"Parliament needs to satisfy itself that the concerns raised recently by the U.S. Congress of forced labour in Shein's supply chains have been thoroughly addressed."

The spokesperson for Shein added: "As a global company serving customers across more than 150 countries, we believe it is healthy to attract scrutiny and transparency and we want to be held to the highest standards." (Reporting by James Davey and Helen Reid; Editing by Mark Potter )