Taxpayer spending on Amazon online computing contracts has topped £1bn, prompting criticism that ministers have become over-reliant on the US tech giant.

A surge in public contracts awarded to Amazon Web Services (AWS), which rents capacity on a vast global network of computers, means the total sum committed to the company has this year reached £1.04bn since 2014, according to public records.

It comes after it secured a multi-year deal with GCHQ to store highly classified intelligence data.

For the first time this year, AWS, a market leader in what has been labelled cloud computing, has accounted for more than half of government spending on such contracts this year.

Figures from GlobalData found that 53pc of cloud spending through the Crown Commercial Service’s G-Cloud service has been with AWS this tax year, compared to 30pc last year, and 14pc in 2018.

UKCloud, a British cloud provider, said the Government risks “falling further into the hands of a few foreign tech giants”.

AWS is the world’s biggest provider of cloud computing, in which customers pay for hosting and processing that takes place at a remote data centre, instead of on their own servers.

Spending on Amazon has increased as the Government has promised to overhaul procurement rules to give more opportunities to smaller providers. European countries are seeking to cut their dependence on Amazon, Microsoft and Google, the three biggest players.

Twenty five contracts have already been awarded to the company so far this year, putting it on track to surpass the 26 awarded last year.

Simon Hansford, UKCloud’s chief executive, called for competition regulators to scrutinise the market.

“The Government’s post-Brexit policy agenda often speaks of cultivating a thriving technology environment at home and taking back control – but the increasing dominance of a single foreign provider is clearly at odds with a competitive, healthy market,” he said.

“One size does not fit all and it is high time for the competition regulator to take a look at the growing lack of diversity in the sector.”

It recently emerged that Amazon had won a multi-year contract with GCHQ and other security services, which alone could be worth up to £1bn over 10 years. The deal, which was not disclosed by the Government, is not included in the public spending figures.

“Amazon Web Services is just one of the Government’s thousands of cloud service providers and our procurement decisions are always based on getting value for taxpayers and the best quality services,” a spokesperson for the Cabinet Office said.