Prime Minister Manmohan Singh [Images], who will undergo heart bypass surgery on Saturday morning, is expected to be back in office in a couple of weeks.

The prime minister will be operated upon by a team of handpicked cardiologists who have been specially flown to Delhi [Images] for the job at 8 am, Congress party spokesperson Manish Tewary told newsmen.

Congress sources said the prime minister wanted to wait till after the Republic Day celebrations on January 26 but he felt uneasy on Friday morning and doctors attending upon him did not want to take any chances and decided to go ahead with the surgery.

The Congress spokesperson, however, refused to comment on whether Pranab Mukherjee [Images], who will be presiding over the Union Cabinet in Dr Singh's absence, would be discharging all the duties of prime minister including holding the nuclear button.

As regards the vote on account in place of the budget in February, Deputy Chairman of Planning Commission Montek Singh Ahluwalia had prepared the details two months ago, but since he is not a minister, the job in the Lok Sabha would have to be done by either Pranab Mukherjee or Union Home Minister P Chidamaram, who was looking after finance ministry before he replaced Shivraj Patil [Images].