A group of MPs and peers sanctioned by China say Chinese officials should not have been invited to the Queen's funeral.
It comes after Parliament voted in April to recognise Beijing's treatment of the Uyghur minority in the Xinjiang region as a genocide.
Senior Tory MPs Tim Loughton and Sir Iain Duncan Smith said it was "extraordinary" that Chinese representatives received an invitation to the Queen's funeral on Monday, following MPs' condemnation of China's actions.
In a letter to the Commons Speaker and Lord Speaker, they said: "We are greatly concerned to hear that the Government of China has been invited to attend the state funeral next week, despite other countries Russia, Belarus and Myanmar being excluded.
"Given that the United Kingdom Parliament has voted to recognise the genocide committed by the Chinese Government against the Uyghur people it is extraordinary that the architects of that genocide should be treated in any more favourable way than those countries who have been barred."
In the letter, also signed by crossbench peer Lord Alton and Labour peer Baroness Kennedy, MPs say they have written to Foreign Secretary James Cleverly to express their concerns.
"It is also particularly inappropriate given that seven parliamentarians including ourselves remain sanctioned by the Chinese Government and you along with the Lords Speaker have quite rightly barred the Chinese Ambassador from attending the Palace of Westminster whilst these unjustified sanctions remain in place," they write.
"It may well be as part of the arrangements for foreign dignitaries attending the state funeral that facilities at the Palace of Westminster will be made available to them before or after attending the service at Westminster Abbey.
"I am sure you will agree that it would be wholly inappropriate that any representative of the Chinese Government should be able to come to the Palace of Westminster and that you can give us your assurance that this will not happen."
Mr Duncan Smith and Tim Loughton, Baroness Kennedy and Lord Alton were all among a group of British MPs sanctioned by China last year.
The move was in retaliation over then-foreign secretary Dominic Raab imposing sanctions on Chinese officials deemed responsible for human rights abuses against the Uyghur people.
Beijing is reportedly considering sending a delegation to the funeral on Monday in Westminster Abbey but is is unclear whether President Xi Jinping will attend.
The Chinese leader is currently meeting Russian president Vladimir Putin at a summit in Uzbekistan.
A statement from the Chinese Embassy reads: "The state funeral of Her Majesty Queen Elizabeth II is an important activity of the UK.
"Foreign delegations attend the activities at the invitation of the UK side to show respect to the late Queen and the people of the UK.
"As the host, the UK side should be familiar with diplomatic protocols and proper manners of receiving guests."
Russian officials are not invited to the Queen's funeral, due to Putin's Ukraine invasion.
A recent UN report expressed concerns that "serious human rights violations have been committed" in the remote northwestern region of Xinjiang.
It claimed the mistreatment of the Uyghurs - a predominantly Muslim ethnic minority group - had been linked to Beijing's avowed 'counter-terror' and 'counter-extremism' policies.
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As foreign secretary, and during her campaign to become prime minister, Liz Truss pushed for Britain to take a hard line against the Chinese Government.
Earlier this month Tory MP Tom Tugendhat - now security minister - urged the government to look at banning the import of all cotton products produced in the Xinjiang region.
Legislation which came into force in the US in June assumes any products made or partially made in the province is linked to forced labour camps.
Invitations to the Queen's state funeral have not been sent to Russia, Belarus or Myanmar while Iran will only be represented at an ambassadorial level, it is understood.