Shepherd wants Hall future clarity
The Belgravia Group's decision to pull out of their move to take control of the Magpies on Friday came just weeks after the Polygon-backed St James' Park Group had done the same and, for now at least, ended months of speculation.
Now Shepherd has urged Hall, who has been in talks over his family's 41.6% stake in the club with the potential suitors, to make his intentions clear.
He said: "Sir John Hall has to decide what his role in the club is. The future of this club is in his hands. He has to decide whether he wants to stick or sell.
"For the sake of the club, the shareholders and supporters, Sir John must decide quickly what he is going to do and make his position public.
"He is perfectly entitled to sell his shares to whomever he wants. But if he wants to sell them, he needs to say so and if, he does not, good, let's all march on together.
"The uncertainty is making it hard for me to run the club. Sir John identified two potential buyers and it has not worked.
"How many more potential buyers has the club to cope with?"
It was the Hall family's investment in the club which saw Newcastle rise through the 1990s back to the upper reaches of the Premiership and establish themselves on the European stage.
However, Sir John stood down as chairman in December 1997 when Shepherd assumed control.
He has steered the club through troubled waters in recent times, dispensing with managers Sir Bobby Robson and Graeme Souness, and has found himself a target for the critics during a troubled season.
But he steadfastly resisted the Polygon and Belgravia approaches and insists the speculation has proved damaging to the club and his efforts to take them forward.
Shepherd said: "The offer period has been damaging and difficult for everyone at the club.
"Everyone at the club from me as chairman down to the manager Glenn Roeder, the coaches, the players and our administrative staff, have been left wondering whether they would have jobs when it was all over.
"If he lives to be 100, is Sir John going to keep trying to sell these shares? Are we going to have this uncertainty forever?
"All I am asking of him is a clear decision. I want him to be honest with me and the supporters.
"The club simply cannot go on dealing with proposed buyers knocking on the door who turn out to be time wasters.
"It is me who has to run the club on a day-to-day basis and this situation is not conducive to running a huge Premiership club.
"Our fans read that Belgravia were supposedly going to put £24million in for new players in January.
"That conjecture created problems by raising fans' expectations and causes clubs to raise their prices when we ask them about players."
Shepherd, who has a 28%-plus holding in the club, also revealed he might consider buying the Hall shares himself.
He said: "I have shown my commitment to Newcastle by buying shares in the club and I have never sold a share. I would consider buying the Hall shares at the correct price.
"I cannot prevent Sir John selling the shares he controls, but if the club I want it to be to the right people. As long as I am here, I am going to do my best for the club.
"But at the same time, I am not going to let any would-be buyer take the mickey out of this club or its supporters by raising false expectations."