The 57-year-old caused a major stir in the wake of Sunday afternoon's 2-0 defeat by Chelsea when he admitted he could not be given enough cash to close the gap on the Premier League's top four in the short term, and that means his side will fight at best for fifth place next season.

That has been interpreted in some quarters as a challenge to Ashley to put his hand in his pocket, while it is yet to be seen just how the relationship between the manager and the recruitment set-up headed by Dennis Wise will work.

But while Keegan insists he will be backed by the owner and chairman Chris Mort, he is yet to be told what his budget might be.

He said: "I don't know, I have not been told. I don't know what is here if I am honest.

"That's not a problem. We will just have to wait and see.

"You really need to be talking to Chris Mort and whoever has just been appointed [deputy chairman Derek Llambias] or Dennis Wise about the finances for this football club.

"It's not my job and I have never been involved in it. That's the truth.

"I cannot help you on that other than saying my job is to ask [vice-president (player recruitment)] Tony Jimenez to go and get players.

"I give them a player and they go and try and get them for us.

"But I am saying that whatever finance will be there, it will not be enough to take us into the top four."

Ashley has ploughed in excess of £100million into the club since completing his £134.4million takeover, launched almost a year ago, to address the debt burden and fund then manager Sam Allardyce's rebuilding programme last summer.

Keegan will hope to be able to compete for, if not the best players in the world, then certainly those who fall into the next category as he attempts to drag the club back to the days when predecessor Sir Bobby Robson secured three successive top-five finishes.

Robson famously took the Magpies from 11th to fourth in a single season with the addition of £16million duo Laurent Robert and Craig Bellamy, although it is that kind of leap which the latest incumbent believes is now an impossibility.

Speaking after receiving the plaudits of the club's fans for the recovery job he has engineered in recent weeks, he said: "With that comes a major responsibility, and that major responsibility is to be realistic with them and tell them I am not going to get enough money to make major changes at this football club.

"I know that already. I do know that much.

"Major changes take massive finance, and it is not massive finance.

"If someone said there would be £40million or £50million, it still would not be enough to get you from where we are."

Meanwhile, Keegan has confirmed that striker Mark Viduka will not play in the final game of the season at Everton on Sunday, and will this week have a planned injection to address his Achilles problem.