The Big Question: Why do so many foreign billionaires want to make their home in Britain?

Why are we asking this now?

The former Thai Prime Minister Thaksin Shinawatra has skipped bail in Thailand in favour of moving to Britain. Mr Thaksin, who owns Manchester City football club, has faced corruption charges in Bangkok but failed to attend a scheduled court appearance on Monday.

Mr Thaksin and his wife, who has just been convicted of fraud and sentenced to two years in jail, were allowed to travel to China from Thailand for the Olympics opening ceremony despite being involved in legal proceedings. Mr Thaksin – who was ousted as Thailand's prime minister in a military coup in 2006 – says he can't get a fair trial due to political interference in the judicial system and would instead live with his family in England, where he has several homes. Thailand's Supreme Court has now issued an arrest warrant for the billionaire.

What are the allegations against him?

Mr Thaksin and his wife are accused of abuse of power in relation to the purchase of state land. Mr Thaksin, together with several former cabinet ministers, is also facing separate accusations of corruption linked to a government lottery scheme. Further allegations concern an improper state loan to Burma, which is alleged to have benefited his family business. There are also outstanding charges of tax evasion against members of his family.

In his statement, Mr Thaksin set out his reasons for not returning home. He said: "What happened to me and my family and my close relations resulted from efforts to get rid of me from politics," he said in the hand-written statement. These are my political enemies. They don't care about the rule of law, facts or internationally recognised due process." Mr Thaksin apologised to the Thai people for his decision to live in the UK, where his daughter is attending university. "If I am fortunate enough, I will return and die on Thai soil, just like other Thais," he said.

Will he be allowed to stay here?

Any alleged wrongdoing is strongly denied and neither Mr Thaksin nor any members of his family are accused of any offences in this country. Under UK law, he is a free man and as a result can go about his business in this country unobstructed.

It is up to the Thai authorities to try to force Mr Thaksin to return to Thailand. It is not for the British government to try to remove him before any formal request has been made. The Thai authorities have to formally ask the UK government to extradite him to Thailand. That hasn't happened yet. But if the Thai prosecutors were to go down this road they would be able to rely on a long-standing extradition treaty between the two countries. They would still need to provide prima facie evidence that Mr Thaksin has committed a criminal offence. Should this happen, it would then be open to Mr Thaksin to challenge evidence in the UK courts. His wealth will then be an advantage to him when it comes to securing the best legal advice. This will normally mean instructing top City immigration solicitors who will be able to find the best QC to fight his case.

Should he be arrested, his lawyers will be able to draw on his vast resources to help persuade the courts to grant him bail.

Can he claim asylum?

It is open to anyone, rich or poor, to claim asylum in the UK. Should Mr Thaksin make an application for refugee status, he will have to show that he is in fear of political, religious or ethnic persecution in Thailand. Since his religious and ethnic background is not thought to be an issue, this may prove to be a high hurdle to overcome. It is much more likely that he will claim that his prosecution in Thailand is politically motivated. But this will not be easy, as the UK recognise the Thai administration as being democratically elected. So far, he hasn't said whether he intends to ask for asylum.

Have other rich businessmen been able to find refuge here?

Yes, especially the so-called Russian oligarchs. The best known is Boris Berezovsky, who, fearing arrest in Russia, fled to London in 2001, where he was granted political asylum. He was charged with fraud and political corruption, but British courts have rejected all three attempts to get him extradited to Russia.

On 29 November 2007, a Moscow court found Berezovsky guilty of massive embezzlement, and sentenced him to six years in jail. The court held that he had stolen 214m roubles (£4.5m) from Aeroflot through fraud, and ordered him to repay it. Berezovsky called the verdict "a farce" and he has successfully argued that the prosecutions are politically motivated to silence his criticism of the Putin regime.

Why do so many Russian oligarchs choose to live in Britain?

Our immigration laws certainly benefit the rich. Other oligarchs, including Roman Abramovich, the owner of Chelsea football club, have also used their wealth to establish themselves in this country.

Any non EU-citizen who has a million pounds and wants to live in the UK can apply for a three-year investor's visa. All the businessman has to show is that they have £1m invested in a business, government bonds or another secure asset that benefits the British economy. There are similar immigration schemes for foreign business people with just £250,000 to invest in a UK company which employs at least two UK nationals.

These visas can be extended for another two years after which the visitor can apply for permanent residence. For all those without this kind of financial wherewithal, the choice is either to apply for a points-based worker's visa or a work permit. Again, after five years it is open to the non-UK national to apply for residency. However, the Home Office does make some effort to investigate the origins of the investment so that the UK can be sure that is the money is not proceeds of crime or dodgy business deals.

Don't they end up as non-doms anyway?

Once your are a British citizen with interests abroad, you can register for "non-domiciled" status, meaning you do not pay tax on earnings outside the United Kingdom. Under plans which took effect in April, anyone who has claimed non-dom status for seven of the past 10 years will have to pay an annual fee of £30,000.

What if you aren't wealthy?

Everyone who wants to live in the UK can only stay here under the six-month visitors rules. If they don't qualify for any of the business-related immigration schemes, and have had their application for asylum rejected, then they will have to leave the UK. Many may choose to move and come back to the UK at a later date. Provided they don't return within six months, this is a lawful way to avoid returning to their home countries.

Are rich foreigners exploiting the UK?

Yes...

* Overseas investors take advantage of generous UK visa schemes to gain residency

* London is the city of choice for those seeking to escape prosecution in their homeland

* Extradition can be dragged out for years by those who can afford the best lawyers

No...

* UK rules are tough enough to stop the wealthy using their money to flout the law

* The Home Office examines investments to ensure they are not used to gain UK residence

* Foreign millionaires only come to the UK because it is a good place to do business