Sir Keir Starmer will urge Britain’s economic regulators to prioritise their mandates to stimulate economic growth as part of a pitch next week aimed at wooing global investors.

Sky News has learnt that the prime minister intends to use a speech at Monday’s International Investment Summit to say his administration will scrutinise watchdogs across a range of industries to ensure that they are not acting as barriers to growth.

The event, which will take place in the City, is being seen as a test of Labour’s economic agenda in the eyes of investors who wield influence over the destination of trillions of pounds of investment funding.

Sir Keir is said by officials to be determined to deliver the message that regulators such as Ofwat, Ofgem, the Prudential Regulation Authority and the Competition and Markets Authority should be focused on the competitiveness of the UK economy.

His speech will come, however, against the backdrop of a financial crisis at Thames Water, Britain’s biggest water utility, which is backed by sovereign wealth funds and pension funds from countries including Abu Dhabi, Canada and China.

One water industry executive said the prime minister’s speech was likely to be interpreted as a signal to Ofwat, the water regulator, that it needed to navigate carefully the implications the collapse of Thames Water would have for international investors’ confidence in Britain.

Reports in recent weeks have suggested global investors have become so alarmed by Ofwat’s approach to the Thames Water crisis that they are reluctant to commit further sums to British infrastructure projects.

On Thursday, the government appointed Poppy Gustafsson, the former boss of cybersecurity company Darktrace, as investment minister, ensuring that the government avoided the ignominy of staging Monday’s summit without a minister for investment being in place.

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Labour’s landslide election victory in July has been rapidly followed by a succession of own goals which have left the prime minister dogged by accusations that he has failed to adapt to being in power.

On Monday, the government will publish an industrial strategy green paper that will highlight more than half a dozen economic growth sectors to be prioritised during this parliament.

Labour will also announce the chair of its Industrial Strategy Council this weekend, according to insiders.

Downing Street declined to comment.