On the eve of new UK rules designed to encourage wealthy migrants to live in the country, an immigration expert has warned people using the new regulatory regime not to expect an easy route to citizenship.

The Conservative/Liberal Democrat government has laid down rules so that foreign investors who bring between £5 million (around $8.1 million) and £10 million to the country can achieve indefinite leave to remain (ILR) within three and two years, respectively. The rules come at a time when people in the financial services industry had warned that the UK was becoming increasingly unfriendly to wealthy individuals. The previous administration introduced a new annual levy on non-domiciled residents and a top income tax rate of 50 per cent.

Under the new ILR regime, which takes effect today, people can be absent from the UK for up to 180 days a year without it affecting their eligibility for ILR.

"While the new rules appear to be a sensible quick fix for the Government to attract much needed funds and talent into the UK, anyone considering this route should take expert advice that provides them with a 360 degree look at their aspirations, assets and objectives for moving to the UK. As with most things in life, if the deal looks too good to be true, it probably is,"said Philip Barth, head of the private immigration law team at Penningtons Solicitors.

"While these changes appear to make it easier for people to relocate to the UK, set up a business and achieve ILR more quickly, if one of their goals is to achieve citizenship, they should be aware that the rules for naturalisation have not been changed. This means that, at best, these new rules will only shave 12 months off the six-year path to a British passport,” he said.

In March, Barth warned that the rules, unless properly understood, could jeopardise, not boost, the chances of citizenship. If a person exploits the 180-day rule to the full, they could exceed the 450 days over a five-year period that a person is allowed to be outside the UK to be eligible for citizenship. The rules could also prove a double-edged issue in terms of investment fund flows, he has said. Once people become permanent citizens, there will be nothing to stop them moving money out of the UK.

Among the changes coming into force today are relaxations for entrepreneurs, including a reduced investment threshold of £50,000 - the standard current threshold is £200,000 - for those with funding from reputable, approved organisations such as registered venture capitalists, business angels or a government department.

In another detail, entrepreneurs can settle in the UK more quickly if they create ten jobs or turn over £5 million in a three-year period, Barth said in a statement.

In March, the London-based law firm Berkeley Law pointed out how the new immigration rules had prompted a sharp rise in the amount of enquiries from people looking to enter the UK. (To view that item, click here).