Shamima Begum: Can Home Secretary stop IS bride from returning home?

The decision by Home Secretary Sajid Javid to try to strip Islamic State bride Shamima Begum of her UK citizenship may play well in the court of public opinion - but what actually is the legal situation?

The rules governing citizenship are covered by the British Nationality Act 1981.

It defines what being a British citizen means in law and how that citizenship can be removed.

However that process also has to adhere to international law which forbids nations from making people stateless by revoking their only citizenship.

In the case of Shamima Begum, Mr Javid will have to prove she has dual British-Bangladeshi nationality.

:: BNA 1981 Section 40 part 2:

The Secretary of State may by order deprive a person of a citizenship status if the Secretary of State is satisfied that deprivation is conducive to the public good.

:: BNA 1981 Section 40 part 3:

Subject to the provisions of this section, the Secretary of State may by order deprive any British citizen to whom this subsection applies of his British citizenship if the Secretary of State is satisfied that that citizen -

(a) has shown himself by act or speech to be disloyal or disaffected towards Her Majesty; or

(b) has, during any war in which Her Majesty was engaged, unlawfully traded or communicated with an enemy or been engaged in or associated with any business that was to his knowledge carried on in such a manner as to assist an enemy in that war; or

(c) has, within the period of five years from the relevant date, been sentenced in any country to imprisonment for a term of not less than twelve months.

:: BNA 1981 Section 40 part 5:

Before making an order under this section in respect of a person the Secretary of State must give the person written notice specifying -

(a) That the Secretary of State has decided to make an order,

(b) The reasons for the order, and

(c) The person's right of appeal under section 40A(1) or under section 2B of the Special Immigration Appeals Commission Act 1997

So for Shamima Begum:

:: Mr Javid has to prove she is a dual national

:: She has to have done something against the interests of the UK and its citizens

:: She has to be given documents outlining why her citizenship is being removed. It is reported that these have been delivered to her family in the UK - and they have been instructed to make her aware of their contents

:: She has the right to appeal

The appeals process is conducted by the Special Immigration Appeals Commission.

The SIAC is independent of the government and allows individuals to appeal against immigration decisions by the Home Office, such as deportations and the removal of citizenship.

Those who are outside of the UK have 28 days to lodge an appeal from the time they receive their Home Office letter.

The Home Secretary could also use Counter-Terrorism and Security Act 2015 to impose a Temporary Exclusion Order.

To do this he would have to show that "he reasonably suspects that the individual is, or has been, involved in terrorism-related activity outside the United Kingdom".

Mr Javid could then impose a TEO which would invalidate Shamima Begum's passport for two years, although this could be extended.

However he would have to allow her re-entry into the UK if she agreed to certain conditions such as taking part in a de-radicalisation programme or reporting to a police station.

Showing that Shamima Begum had been involved in "terrorism-related activity" would be difficult.

In any case TEOs can be readily challenged in the courts on the basis of "fairness and reasonableness".