Tony Adams fears he will not be given time to succeed at Portsmouth, with the club on the brink of being sold to a consortium led by the head of one of South Africa’s largest gold-mining companies.

The Times has learnt that Greg James, the chief executive of Central Rand Gold, is the man leading a £70 million takeover bid that will cast immediate doubts over the future of Adams as manager.

The former Arsenal and England defender is just beginning to assemble his coaching staff at Fratton Park and today he continued that process by appointing John Metgod, the former Nottingham Forest midfielder, as his first-team coach.

Adams says he is determined to remain at the club for a "very long time", although he admits he is concerned that he may not be given the time he needs to become successful at Fratton Park.

"I do worry I'm not going to be given time because we are very driven by results," he said. "We are living in a society of now."

"I'm planning on being at this football club for a long time, and the people here have given me no reason to think otherwise," Adams added. "If I am given time I am sure I will be able to. I have confidence in my ability to be able to do that."

The consortium planning to buy the club has held a series of discussions with Alexandre Gaydamak, the Portsmouth owner, in the past week and is understood to be confident of striking an agreement to buy the club from Devondale Investments, the holding company. He is being assisted in negotiations by Pini Zahavi, the influential Israeli agent, who knows both men well and may be retained in a consultancy role if the bid is successful.

Potential managerial targets would include Avram Grant, who served as director of football at Portsmouth before his spell as first-team coach at Chelsea, and Slaven Bilic, the Croatia head coach. Grant, who has close links with Zahavi, is understood to have asked Hajduk Split, who have offered him the manager’s job, if he can delay giving an answer for two weeks while he explores other options.

Adams, who was promoted from assistant manager after the departure of Harry Redknapp to Tottenham a fortnight ago, admits he is concerned by the instant impact supporters now demand.

"At the moment everyone is very supportive, and I am very confident. I'm very positive and I'm very happy," he said. "I think if I am given time here I can be successful, so time is a fear."