British companies will be protected from foreign buyers who do not have their best interests at heart under proposals contained in the Conservative manifesto.

The document said that the party “believes in the rights of business owners” and “wants Britain to be a global nation that is competitive, outward-looking and open for business... which welcomes overseas investors”.

However, it warns its aim of being “the best country in Europe for doing business” must not be expense of welcoming investors “whose success is driven by aggressive asset-stripping or tax avoidance”.

To prevent this the Conservatives say they will update rules governing mergers and takeovers, requiring:

bidders to be clear about their intentions from the outset of the bid process

that all promises and undertakings made in the course of takeover bids can be legally enforced afterwards;

that the government can require a bid to be paused to allow greater scrutiny.

The manifesto also says that foreign ownership of businesses in sectors critical to the national security - such as defence, energy and telecoms - will come under special scrutiny.