Congress candidate from Gautam Budh Nagar, Ramesh Chand Tomar, on Thursday delivered a severe jolt to his party when with just a week to go for the elections, he joined the Bharatiya Janata Party. His decision left the party workers disappointed and angry. Mr. Tomar met BJP chief Rajnath Singh in New Delhi in the morning and re-joined the party he had left in 2009. Before joining the Congress, he had won parliamentary elections from Ghaziabad four times on a BJP ticket.

He had fought the elections from Gautam Budh Nagar in 2009 on a Congress ticket but lost to BJP’s Dr. Mahesh Sharma, who is again the party candidate from the constituency.

The Congress election office in Sector 36 here, which just a day ago was abuzz with activity, wore a deserted look. The posters, vans, flags and other campaign paraphernalia with Mr. Tomar’s face were no longer occupying space outside the office. In fact, a poster — that had the photographs of various Congress leaders — sported a gaping hole where Mr. Tomar’s image once was.

Locals in the area said they suspected something was wrong on Wednesday night when the office was locked up.

“Party workers started arriving at 11 a.m. on Thursday and they found the office locked. Soon they heard what had happened and started protesting and tearing posters. The police had to be called to pacify them,” said a vendor whose stall is outside the office. At another election office, the party workers burned an effigy of Mr Tomar and threw shoes at his poster.

Mr. Tomar’s last-minute move has left the Congress without any candidate for the seat, while BJP workers are celebrating the return of their former leader.