According to the BBC, officials recently discovered that most of the UK's powers to impose sanctions on other nations will disappear after it quits the EU.
They include the ability to impose trade embargoes, asset freezes or travel bans.
A hastily-drawn up consultation document on the plans began last Friday, and the Government hopes to have the new laws in place as soon as possible after the general election.
The EU currently imposes 30 sanction regimes on countries including Russia, North Korea, Syria and Iraq.
Under the new laws, which are expected to be passed without any substantial delays, Britain will be able to impose sanctions itself for the first time.