The entrepreneur Dale Vince has made a fresh approach to the owner of The Guardian in a bid to persuade it to open talks with him about The Observer, days after its sale was agreed to a digital start-up.

Sky News has seen an email sent at the weekend by Mr Vince to Ole Jacob Sunde in which he asks whether an interview given to a Sunday newspaper indicating that he was open to other talks about The Observer’s future represented “a change of position” from the left-wing newspaper publisher.

Mr Vince, who had held talks with the Guardian Media Group chair, Charles Gurassa, prior to last week’s confirmation of The Observer’s sale to Tortoise Media, wrote to Mr Sunde: “I am ready to engage with your team if you are serious.

“I don’t imagine you expect a blind bid, or would take one seriously, [and] a discussion on the numbers therefore would be the right starting place. Is that possible?”

“Broadly speaking my intentions for the Observer match your own; I’m a fan and a reader and a believer in media pluralism.

“I operate a group of companies that made £38m last year on roughly £500m of turnover – all operating in the green economy.

“The Observer clearly needs a digital presence in order to stand alone, I believe the print version is essential to maintain – and the Guardian subscriber model is I believe the right approach.”

Mr Vince, who has founded a string of green energy businesses and owns Forest Green Rovers Football Club, is understood to have written to Mr Sunde after the Scott Trust chair was asked by The Sunday Times whether he would still consider selling to a rival to Tortoise Media.

“Of course, at any time in the process, you would listen to people coming to talk to you,” Mr Sunde told The Sunday Times.

“And we will listen, as we have done with all the different bidders that have come.”

However, his comments appeared to be at odds with a subsequent email sent by Mr Sunde in response to Mr Vince’s latest overture – which has also been seen by Sky News.

“Our position hasn’t changed and we are still not in a position to have discussions with other interested parties,” Mr Sunde told the entrepreneur.

“You are the only person who has addressed us, revealing your identity and intentions.”

Despite saying that the Scott Trust had no grounds to talk to rival bidders, Mr Sunde concluded his email: “May I suggest that any further queries are directed to [Charles Gurassa] at this point.”

A GMG spokeswoman confirmed on Monday that the company remained in exclusive discussions with Tortoise Media, having said last Thursday that it expected a formal sale agreement to be signed within days.

The Scott Trust has pledged to invest £5m into Tortoise Media in exchange for a stake and a board seat, in an attempt to placate furious Guardian and Observer journalists.

Last week, they went on strike for two days in protest at the sale.

On Friday, Mr Vince accused the newspapers’ owners of telling “a complete untruth” about his interest in The Observer.

“I don’t understand why my interest in the Observer continues to be mischaracterised by the Guardian/Scott Trust,” he told Sky News.

One source said that the apparent mixed messaging from GMG and the Scott Trust raised important questions about corporate governance at the two organisations, and said the “fiasco” would put serious pressure on the organisations’ leadership.

Paul Webster, who until last month was The Observer’s editor, accused Mr Sunde of failing to consult him or colleagues on the paper about the sale.

If the deal with Tortoise Media completes, it will see The Observer in new ownership for the first time since the early 1990s.

Founded in 1791, it is the oldest Sunday newspaper in the world.

Its takeover by a digital media startup will underline the shifting dynamics sweeping the global news media landscape.

GMG and the Scott Trust declined to comment beyond confirming the accuracy of Mr Sunde’s quotes in The Sunday Times.