London: British Prime Minister Theresa May on Tuesday unveiled a major post-Brexit overhaul of the UK's immigration system, which she said is aimed at a level playing field for nationals from all countries by ending "freedom of movement once and for all" for European Union (EU) citizens.

Indians may benefit from the new rules, which will focus on highly-skilled migration as opposed to low-skilled workers, but an added obligation on companies being required to sponsor families of such high-skilled professionals may prove a hurdle in the long term.

"When we leave (the EU) we will bring in a new immigration system that ends freedom of movement once and for all. For the first time in decades, it will be this country that controls and chooses who we want to come here," May said in a statement.

"It will be a skills-based system where it is workers' skills that matter, not where they come from. It will be a system that looks across the globe and attracts the people with the skills we need, she said.

"The UK government said the new so-called skills-based system will make sure low-skilled immigration is brought down and set the UK on the path to reduce immigration to sustainable levels," a key manifesto pledge of the ruling Conservative Party.

The new regime, details of which are yet to be fully specified, is expected to be in place by 2021 once the transition period for Britain's exit from the EU is complete.

Under rules for skilled workers, applicants will continue to be required to meet a minimum salary threshold, which may be hiked further, and have their families sponsored by their future employers.

"Successful applicants for high skilled work would be able to bring their immediate family but only if sponsored by their future employers," the government statement noted.

There are also plans to introduce in-country security checks to be carried out to make operations faster at passport control at the borders, a similar system of prior authorisation currently operated by the US.

This new swift system of e-gate visa checks for visitors coming into the UK on short-stay tourist or business trips will be limited to low risk countries , which is unlikely to include India.

The proposals follow a crucial government-commissioned report from the Migration Advisory Committee (MAC) last month, which had recommended that high-skilled workers must be given priority over visa applications from low-skilled workers.

The report was based on an immigration policy that had a level playing field for EU nationals and applicants from other countries, proposals which were accepted by the UK Cabinet last week.

A White Paper detailing exactly how the new system will work will be published in the coming weeks, ahead of a new Immigration Bill to be laid out before Parliament next year, the government said.

The announcement was widely expected since the Migration Advisory Committee had called for an end to preferential access to EU workers after Brexit.

Under the EU's current free movement rules, citizens from within the 28-member economic bloc have so far been able to enter the UK freely and look for work on arrival as opposed to strict visa norms that apply to non-EU workers from countries like India.

The current cap on skilled workers is set at 20,700 per year for migrants from non-EU countries like India, something the committee had recommended should be done away with.

However, whether this would ultimately benefit skilled professionals from countries like India will depend on the additional requirements imposed upon applicants and the UK-based companies seeking to employ them.

UK Home Secretary Sajid Javid will lay out some of the contours of the new plans as part of his speech to the ongoing Conservative Party annual conference in Birmingham later on Tuesday.

The major immigration overhaul announcement is being seen as a counter-point to the arrival at the conference of the British PM's key Brexit rival, former foreign secretary Boris Johnson, who is due to make a speech attacking her strategy on negotiating an exit deal with the EU.

The issue of migration continues to be a highly contentious one, with control over borders to end free movement of people from member-countries having played a crucial part in the campaign for leaving the EU in the June 2016 Brexit referendum.