Concerns are mounting in the legal profession over new immigration rules described by the United Kingdom Border Agency (UKBA) as the biggest shake-up of border security in 45 years.

Tiers 2 and 5 of the points-based system, which go live today, require 20,000 employers to have registered as sponsors to continue bringing workers into the UK from outside Europe.

However only 1,000 employers have so far done so, said Alison Harvey, secretary general of the Immigration Law Practitioners Association. ‘That’s a recipe for disaster.’ She blamed a ‘proliferation of impossible-to-navigate UKBA guidances’.

Tier 2 of the rules covers skilled workers, while tier 5 applies to sportspeople and others temporarily in the country. Both tiers require employers to register as accredited sponsors. They must also keep records of sponsored individuals, including contact details and copies of their now mandatory identity cards.

Meanwhile, Laura Devine of London firm Laura Devine Solicitors raised concerns about the UKBA’s new online system for registering certificates of sponsorship. The main problem, Devine said, is that the system does not authenticate the identities of users creating a certificate – essential when mistakes could lead to the revoking of an employer’s license.

The UKBA said that ‘only nominated people within an organisation can gain password-controlled access to issue certificates, which makes them readily traceable’.