Mr Kwarteng is due to make a decision to approve or refuse the application by October 21. The £1.2bn project would see an undersea power cable land at Eastney from France.
There is fierce opposition in Portsmouth against the cable with campaigners saying it would cause chaos for years while it is installed and run up to Lovedean.
Aquind director Alexander Temerko has donated £700,000 to the Conservatives, while Aquind owner Viktor Fedotov’s businesses have also donated £700,000, the BBC reported.
The News has previously reported how former business secretary Alok Sharma, and other politicians, have recused themselves from being involved in the decision.
On Sunday Mr Kwarteng was asked by the BBC’s Andrew Marr if the party should would return the cash if Aquind is given approval.
The business secretary said: ‘The way in which these deals are done, not the deal, we rely on official advice.
‘So as secretary of state I will get official advice as to whether to approve or reject the application, and I will be guided by that advice.
‘It would be pre-emptive of me to say which way.’
In 2019, when a business minister, Mr Kwarteng wrote to Mr Temerko about his ‘continuing support’ for projects which 'of course includes the Aquind project'.
Asked by Marr about his previous support for Aquind, he said: ‘I've said - I've never commented on this specific, specific, project – I've said very broadly I'm very much in favour of more interconnectors because they can actually get electricity sources of power cheaply from the continent and in many cases it helps with decarbonisation.’
Asked again about the donations and should they be returned if Aquind is approved, he said: ‘I will be relying on official advice.
‘The officials have not been compromised or funded by these businessmen and they will have an objective view, and I will be strongly guided by it.’
The Conservative Party told the BBC that ‘policy is in no way influenced by the donations the party receives’ and that donations are part of the democratic process.
The Guardian reported lawyers for Mr Fedotov told the newspaper: ‘Mr Fedotov has never had any interest in British politics and has operated in an open and transparent manner throughout the course of his career.’
An Aquind spokesman previously told The News it ‘fully complies with all relevant laws and regulations’.
He said: ‘Aquind Interconnector has been carefully designed to avoid and minimise impact on the environment and local communities.’
He said it would create 500 jobs, meets government policies and objectives and could transmit five per cent of Britain’s electricity annually.