New Delhi: Prime Minister Manmohan Singh on Friday greeted Congress president Sonia Gandhi on her 65th birthday, an official said.

“The Prime Minister spoke to Gandhi over phone this (Friday) morning and conveyed best wishes for her birthday,” a spokesperson of the Prime Minister's Office (PMO) said.

Manmohan Singh also sent her a bouquet, he added.

Gandhi, who underwent surgery abroad in August for an undisclosed ailment, had indicated earlier that the celebrations should be low-key.

Party sources said that might be the reason Manmohan Singh and other leaders did not visit her personally. Union ministers and senior party leaders also wished her over the phone, they added.

Gandhi had asked party workers 'to avoid inconvenience to the public' while celebrating her birthday, Congress general secretary Janardhan Dwivedi had told reporters recently.

She also appealed to party workers from other states to avoid travelling to New Delhi on the occasion, Dwivedi had said.

Gandhi is the longest-serving president of the 125-year-old Indian National Congress. She has been elected president of the Congress since 1998 when she entered active politics.

Born Antonia Edvige Albina Maino in Lusiana - a village in Veneto in Italy - Dec 9, 1946, she married former Indian Prime Minister Rajiv Gandhi in 1968 - then a student in Cambridge.

She came to India in 1968 and became an Indian citizen in 1983.

Leading the Congress back to power in 2004 after a gap of six years, she declined to become prime minister. Instead, she has been chairman of the ruling United Progressive Alliance (UPA) since then.

She is also chairperson of the National Advisory Council (NAC).