Big Sam successfully barters for Joey

The 24-year-old Manchester City midfielder is understood to have agreed a five-year deal after undergoing a medical following talks with the Magpies' boss as West Ham attempted to hijack a £5.5million deal.

Neither the Magpies nor City have yet confirmed the deal, although they are expected to do so within the next 24 hours, but Barton - on leaving St James' - told Sky Sports News: "It's very close now. I was impressed by the stadium and everything else that goes with it.".

Barton headed across the Pennines after being given permission to talk to Newcastle, and arrived at the club's Darsley Park training ground along with Allardyce.

He left with Newcastle physio Derek Wright several hours later to start the medical as agent Willie McKay continued negotiations at St James' Park, but later made his way to the stadium to seal his move.

Allardyce appears to have successfully sold the club to a man ready to launch a new phase of his career after the training ground bust-up with team-mate Ousmane Dabo which hastened his exit from Eastlands.

The manager's powers of persuasion could hardly have been put to more timely use with the Hammers ready to offer Barton an equally lucrative alternative after also agreeing a fee with City.

Barton's situation was directly linked to West Ham's efforts to sign Newcastle captain Scott Parker, whose proposed move to Upton Park should now be completed with the Magpies having secured his replacement.

It proved a good day for Allardyce, who also appears to have persuaded Middlesbrough striker Mark Viduka to opt for Tyneside rather than east London with the same two clubs among those chasing the 31-year-old Australian.

It is understood Viduka has agreed in principle to join the Magpies after turning down the offer of an extended contract at the Riverside Stadium, and will hold talks later this week.