Singh is understood to have been called here by the high command in the wake of the allegations by BJP Leader Arun Jaitley that he had taken a "bribe" from a private company for extension of a project.
He is expected to meet Congress President Sonia Gandhi and possibly Rahul Gandhi to explain his position in the matter at a time when Congress is seeking to take a high moral ground on the issue of corruption prodded by party vice-president.
As he arrived here, Singh insisted that he had taken no bribe and issued an eight-page statement seeking to rebut Jaitley's charges point by point.
"Frustrated BJP leaders are fabricating false stories and twisting and tampering facts to suit their convinence. They have been waging the same old issues pertaining to my income tax return and loan taken by my family, which have been replied and clarified time and again and there is nothing material or new in them" Singh said.
"As the Congress party and the government in the state has started to grow from strength to strength and the wrongdoings of the previous BJP govenment especially former Chief Minister Prem Kumar Dhumal and his sons are getting exposed, personal attacks against me have grown in equal momentum and volume," he said.