His timing, just three days after Farnborough’s big FA Cup match against Arsenal, has left fans, sponsors and the entire town’s community reeling.
Up to 6,000 fans made the trip to Highbury on Saturday in carnival mood, blissfully unaware that Mr Westley had already made plans to leave.
When he arrived at the club in 1999, Mr Westley was hailed as a hero. He cleared crippling debts and promised to take the Nationwide Conference team into the Premiership within ten years.
He ploughed thousands into new players, changed the club’s colour back to the original red and white, gained promotion from the Ryman Premier League and renamed the ground after his Aimita corporation.
He has offered his 51% controlling share of the club back to current shareholders — mainly Boro fans.
Although he leaves the club debt free, millionaire businessman Westley is understood to have taken some of the profits from the FA Cup — estimated at half a million pounds — with him. Up to ten players could also follow him.
It is a bitter pill to swallow for the loyal supporters, players and backroom staff, who had high hopes of a bright future under the management.
But Westley had become increasingly frustrated with lack of progress over his plans to upgrade the ground at Cherrywood Road to League standard.
On Wednesday morning the 34-year-old, who led Farnborough to the fourth round of the FA Cup, was unveiled as the new manager of Nationwide Conference rivals, Stevenage.
Westley has decided to pursue his ambition of top-flight football with a club currently near the bottom of the league.
The main factors setting the two clubs apart are the impressive facilities at Stevenage’s Broadhall Way ground and a bigger fan base. Farnborough has one of the worst attendance records in the league.
The Cherrywood Road ground is owned by Rushmoor Council and council officials had been trying to thrash out a deal to upgrade it.
Last year Westley was hoping for a substantial council grant. But officials refused to hand over the money until a number of conditions were met, including the payment of outstanding rates, thought to be a four-figure sum.
Executive member for leisure and promotion, Cllr David Clifford, revealed that the club still owes the money and the council will be still looking for payment.
He said: “The club do still owe outstanding business rates from some time ago, the same as what Aldershot Town pay, and the same money that Graham Westley agreed to pay when we negotiated a ground upgrade with them last year. This is a club debt and still needs to be recovered.”
Cllr Clifford also strongly refuted claims by some fans that the council helped drive Mr Westley out of the borough as a result of their ongoing battle to secure a long-term future for the club in the Football League ground.
He added: “Any fan with half an idea of what’s happened knows that Rushmoor Council has been 150% supportive of Farnborough Town Football Club and I take exception to those suggestions.
“Rushmoor has been, and will always be, there for Farnborough Town FC. We have the club at heart and are the most reliable friend they have got.”
Farnborough MP Gerald Howarth said that he was disappointed, but not surprised, by the departure of Westley.
“I have tried very hard over the last couple of years, together with officers at the council, to find an alternative site away from Cherrywood Road. The problem has been that there is very little spare land in Rushmoor for a new stadium.
“He is a young man with very high ambitions and I take nothing away from his determination.
“He did a lot of good things for the club and has wiped out much of their debt.
“The simple fact is that there was not the scope at Farnborough for further development.”
Mr Howarth, who was at Highbury on Saturday, urged the fans to get behind the club at this difficult time.
“I hope that the people of Farnborough have really been fired up by the club’s success. Even if a third of those supporters who travelled to Arsenal came to the home matches, the club would really be in business.”
Club sponsors have also been left reeling by the announcement.
Fleet-based technical recruitment firm Alexander Francis Limited has ploughed thousands of pounds of sponsorship into the club.
Managing director Stephen Gorys and his sales director wife Shelley said they were both disgusted by Mr Westley’s actions.
Mr Gorys said: “It really is shocking. To desert the team and more importantly the loyal supporters is a disgrace.
“As a relatively new sponsor in the last two years, we and many others were led to believe there was a long-term commitment from Graham Westley to the club.”