Loloahi Tapui, 27, appeared at Southwark Crown Court in London
Attorney General Baroness Scotland's former housekeeper has admitted possessing a false document, but has denied intending to use it for fraud.
Loloahi Tapui, 27, pleaded guilty at London's Southwark Crown Court to using a passport with a fake visa stamp.
But the Tongan denied intending to use it to establish facts about herself and to earn money as a cleaner.
Baroness Scotland, Britain's top legal adviser, will appear as a prosecution witness at Ms Tapui's trial in April.
The UK Border Agency said the attorney general took steps to check Ms Tapui's right to work, but had not kept a copy of documents, which would have helped her prove she had gone through the correct process.
She apologised for what she called a "technical breach" of immigration rules and paid a £5,000 fine over the matter last year - but opposition parties demanded her resignation.
Leave to remain
The court heard that Ms Tapui pleaded guilty to having a false visa stamp in her passport, although the passport itself was genuine.
Defending counsel Christopher Hehir said the stamp purported to be issued on 12 September 2005 and falsely claimed she had been granted leave to remain in the UK for three years.
Baroness Scotland was fined Ł5,000 over the affair
Ms Tapui denied intending to use the false document "for establishing, ascertaining or verifying registrable facts about herself", including her "identity and residential status".
She also denied intending to use it to earn money by working as a housekeeper.
Her trial on fraud charges will begin on 6 April. Baroness Scotland, who oversees criminal cases in England and Wales, will appear as a prosecution witness.
Ms Tapui, who is on bail, left the court with her publicist Max Clifford.
If convicted of fraud, she could face up to 10 years in prison. She also faces a charge of overstaying her visa.