The government's senior law officer has admitted breaking the law. Baroness Scotland claimed today that she "made a technical breach of the rules" by employing a housekeeper who was a migrant with no right to work in the United Kingdom.

But that argument does not stand up. What the Attorney General did was contrary to section 15 of the Immigration, Asylum and Nationality Act 2006.

Lady Scotland should know this better than most people since she was one of the ministers responsible for the legislation when it was going through Parliament.

Section 15 allows a Secretary of State - in this case Lady Scotland's Cabinet colleague, the Home Secretary - to issue a notice requiring an employer to pay a penalty. This goes into the Consolidated Fund, like a fine.

But the section says that the employer is excused from paying a penalty if she shows that she complied with any prescribed requirements.

These are set out in a code of practice.

The code makes it clear that an employer will be excused paying a penalty only if he or she made a full check and did not know that the employee was not permitted to take the work in question.

A full check requires the employer to make and keep copies of identity documents. Simply inspecting them, as Lady Scotland did, amounts only to a partial check.

The maximum penalty for a first infringement is £5,000 per worker. Employers are also liable to have their names published.

Should Lady Scotland stand down? There are many reasons why she should not.

• She did not knowingly employ someone not entitled to work in Britain.
• She did check her housekeeper's documents and pay Loloahi Tapui's tax and national insurance.
• Though unlawful, her actions were not criminal.
• She co-operated with the UK Border Agency and paid her penalty.
• She has performed a valuable service in alerting employers to their responsibilities.
• She is thought to have been the first individual employer penalised under this section; all the others were businesses.
• She is good at her job and there is no obvious replacement of her calibre.
• Unless Labour win the next election, she has only a few more months to serve as Attorney General.

Offering her resignation would have been an honourable thing to do. But Gordon Brown certainly doesn't want it.

Maybe the embarrassment Lady Scotland has suffered is punishment enough.