As a supporters' boycott of official Newcastle United merchandise began in earnest yesterday, the growing disenchantment with Mike Ashley's stewardship of the club among local businesses has also become apparent. Dissatisfaction with the hierarchy at St James' Park has spread to the prawn sandwich brigade as well as the terraces, with Newcastle failing to sell a host of lucrative corporate packages.

As of last night, the club were still advertising sponsorship deals for eight Barclays Premier League home matches this season, each of which are worth between £7,000 and £7,500. For the game against Blackburn Rovers on September 27, a dressing-room sponsor (worth £3,000) and a match-day programme sponsor (£2,500) are being sought.

While Ashley, the owner, has signalled his intent to ride out the protests after Kevin Keegan's resignation as manager last week, supporters aim to make life uncomfortable for the billionaire sportswear manufacturer. The “No More Geordie Cash for Ashley” campaign, established by the influential true faith and The Mag fanzines, has already had an effect: at 11am yesterday, there were no customers in the club's flagship stadium superstore.

Newcastle are continuing the process of seeking a successor for Keegan, although there are few, if any, candidates who could hope to quell the rebellious mood on Tyneside. Gustavo Poyet, the Tottenham Hotspur first-team coach, remains the bookmakers' favourite and is reported to have spoken to the club, but his close association with Dennis Wise, the Newcastle executive director (football), would not make him a popular appointment.

Poyet is understood to have concerns regarding politics at the club and the uncertainty about Ashley's plans - representatives of Anil Ambani, the Indian businessman, are said to be in England this week to discuss the possible purchase of a Premier League club - as well as a reluctance to move north.

“I'm very happy [at Spurs],” Poyet said last night. “This is just speculation and it's all too easy because of my relationship with Dennis Wise. It's nothing to worry about and all I intend to do is relax and continue with my job.”