The chairman of Muslim charity Interpal has expressed outrage at newspaper reports that the US is putting pressure on UK ministers to blacklist it.
Interpal is one of the largest Muslim-led charities in Europe
The Sunday Telegraph also says Israel's ambassador is to hold talks with a Treasury minister to demand action.
Interpal chairman Ibrahim Hewitt denied the charity had terrorist links.
The charity helps Palestinians in need and was chosen by MP George Galloway to receive an estimated £160,000 from his appearance on Celebrity Big Brother.
US President George Bush has declared Interpal terrorist organisation but Mr Hewitt said no evidence had been found to support this.
He added that Interpal had been cleared of any wrongdoing by the UK's Charity Commission.
Britain's top Jewish body last year apologised for branding Interpal a "terrorist organisation".
In an out-of-court settlement, the Board of Deputies of British Jews said it should not have described the charity in these terms.
Interpal, which was established in 1994, is one of the largest Muslim-led charities in Europe and says its funds humanitarian, educational and medical projects in the Palestinian territories.
The charity, which spends approximately £5m a year, insists it keeps exhaustive records and audit trails of how its Palestinian partners spend money and has received the backing of Mr Galloway.
The charity is set to benefit from the Respect MP's estimated £60,000 fee for appearing on the show, in addition to an estimated £100,000 from text message voting.
Mr Hewitt told BBC News: "I have concerns that the Treasury minister will give the time of day to a foreign country over a British charity that has been cleared of any wrongdoing by the government's own bodies.
"We haven't done anything wrong. We operate according to the laws of the land under the guidelines laid down by the Charity Commission."
Mr Galloway, the Respect MP for Bethnal Green and Bow, has been criticised by a number of his constituents for his decision to appear on the television show.