LONDON (Reuters) - Britain will intervene to block takeovers and corporate deals that threaten national security, the government said on Wednesday, publishing details of new laws covering potentially sensitive sectors such as defence and energy. The National Security and Investment Bill will give ministers new powers to scrutinise and intervene in “malicious” foreign investment, addressing long-standing concerns that some deals could compromise security or vital infrastructure. “Hostile actors should be in no doubt – there is no back door into the UK,” said business minister Alok Sharma. “This bill will mean that we can continue to welcome job-creating investment to our shores, while shutting out those who could threaten the safety of the British people.” Earlier this year, ministers blocked Chinese communications firm Huawei from parts of its communications network over concerns about spying. In 2016 Britain delayed a nuclear power project in England over concerns about Chinese state funding. Both episodes drew criticism from Beijing but highlighted an increased wariness over threats to national security, and doubts about existing legislation which provides only limited scope for government intervention. The United States and Australia have recently upgraded oversight powers. The new bill will ask companies to seek approval for any potential deal - from takeovers to asset and intellectual property sales - involving a range of sectors, such as defence energy and transport or artificial intelligence and encryption. The government said the vast majority of these transactions would be approved without intervention, and sought to offset concerns about the creation of barriers to investment by promising decisions within 30 days. The laws would explicitly state that national security is the only ground for intervention. Firms which fail to comply could be fined, and executives could be jailed. Any transaction where notification is deemed mandatory would be declared legally void if procedures are not followed.