LONDON- Britain's post-Brexit immigration system will not put a cap on numbers but will prioritise high-skilled labour and end special treatment for European Union nationals, according to a policy paper published by the government on Wednesday.

The system will aim to reduce annual net migration to "sustainable levels" as set out in the governing Conservative Party's 2017 election pledge, the paper said. That pledge was to reduce the annual number to below 100,000.

Skilled workers coming to Britain under the new system will have to be sponsored by a company and will be subject to a minimum salary threshold, the level of which will be set following a consultation with businesses over the next year.

There will also be a transitional temporary worker scheme, which will allow EU nationals and workers of any skill level from other "low risk" countries, to come to Britain without a job offer for up to 12 months at a time. This will be reviewed in 2025.

(Reporting by Kylie MacLellan, editing by Elizabeth Piper) ((kylie.maclellan@thomsonreuters.com; +44 207 542 0401; Reuters Messaging: kylie.maclellan.thomsonreuters.com@reuters.net))