A senior Tory MP lobbied Matt Hancock – while he was Health Secretary – via text message on behalf of the private health firm he was paid by, it has emerged.

WhatsApp exchanges show Owen Paterson's persistence over a multi-million pound Covid testing contract for Randox Laboratories. The company eventually secured a £133million deal.

The dossier, disclosed by the Government yesterday after a battle by opposition MPs, also reveals how Mr Hancock bent over backwards to pass on Mr Paterson's requests to officials.

Former Northern Ireland secretary Mr Paterson quit as an MP after he was found to have breached strict lobbying rules in his £99,996-a-year work for Ulster-based Randox – and a disastrous attempt by Downing Street to save him from a Commons suspension.

Mr Hancock resigned as health secretary in June last year after he was caught on CCTV kissing his aide Gina Coladangelo in breach of Covid rules.

The 88 pages of evidence published yesterday show Mr Paterson first struck up a WhatsApp conversation with Mr Hancock on January 26 2020, days before the first confirmed Covid cases in the UK.

He gave out the email address of Randox's boss and promised the firm could provide quick tests for the disease. Mr Hancock assured him minutes later: 'Thanks Owen. I will look into it.'

In February, Mr Paterson texted again, concerned that Public Health England (PHE) was dragging its feet: 'It is now 19 days since PHE last contacted Randox at your request ... PHE's attitude looks incomprehensible given current developments and time pressures.'

He also wanted to lobby Mr Hancock in person, asking: 'Are you voting today? Can we discuss briefly?' Mr Hancock replied: 'Are you sure? I chased them again about it yesterday.'

Mr Paterson responded that 'sadly' there had been no contact and bemoaned the fact that PHE had 'no sense of urgency or understanding of the speed of the new test'.

Just a minute later, Mr Hancock forwarded the complaint to an unnamed colleague, writing: 'From Owen Paterson below. Could you please ensure PHE get on this.' Days afterwards Mr Paterson complained again that PHE had refused a request of Randox and called the situation 'exasperating'.

Again Mr Hancock forwarded his message to an official with the comment: 'See above from Owen Patz. I am very worried about this. Please can I have chapter and verse on our engagement with UK life sciences for Covid purposes.'

On March 1, Mr Hancock received an email from a senior Department of Health official assuring him that 'Randox has been prioritised'. By the end of the month, the firm had secured the £133million contract.

A government spokesman said: 'There are robust rules and processes in place to ensure that conflicts of interest do not occur and all contracts are awarded in line with procurement regulations and transparency guidelines ... The documents given to the House show no evidence of any breach of these principles.'

Randox said: 'It is clear from these papers that Randox contracts were awarded in full compliance with government procedures and protocols.'

A spokesman for Mr Hancock insisted: 'The extensive transparency publication proves Matt did nothing wrong.'