The television sales consultant known as ‘Mary Queen of the Stores’ has called on the government to block Shein’s proposed London stock exchange listing.

Mary Portas, who carried out inspections of Britain’s high streets for David Cameron’s coalition government, spoke as the Say No to Shein campaign’s online petition neared its target of 35,000 signatures.

The China-founded fast fashion company is expected to seek a £50bn valuation in an initial public offering (IPO) later this summer or early autumn.

The prospect of a London listing comes after a backlash in the US, where Chinese companies have generally faced a hostile reception due to alleged state ties.

Sky News revealed in early June that the company was close to filing a prospectus with the Financial Conduct Authority and was later said to have taken the step, according to Reuters news agency.

Shein’s critics say the UK government should block the application until it completes a thorough investigation into the company’s labour practices, environmental impact and tax arrangements.

They also face charges related to counterfeiting branded products to sell at discounted prices.

“Why are we as a country considering embracing a company like Shein on the London Stock Exchange?” said Ms Portas.

“This is a company accused of unethical business practices, modern slavery and breaches of employment laws. Surely we are better than this?”

Last month, a separate UK-based group called Stop the Uyghur Genocide launched a legal challenge to block Shein’s London IPO.

The company has not commented on the petition, but has previously said it is committed to respecting human rights and has a zero-tolerance policy against forced labor.

Shein executives met with Conservative and Labour politicians ahead of the general election.

Labour has previously signalled its conditional support for a Shein IPO, but said it would have to be regulated in the UK.

The company’s current base is Singapore.

The UK government, like its Conservative predecessors, is keen to strengthen Britain’s appeal as a place to do business after other major financial services destinations such as New York benefited from new business after Brexit.