New Delhi, Sep 17: BJP president Amit Shah and many senior party leaders visited ailing Goa Chief Minister Manohar Parrikar at the All India Institute of Medical Sciences (AIIMS) here on Monday.

Sources in the premier hospital said although 62-year-old Parrikar "is not critical", he was under observation. He is admitted to the old private ward under Dr Pramod Garg, professor of gastroenterology.

The visits by Shah and other senior leaders came after Goa's main opposition party, the Congress, submitted a memorandum to Governor Mridula Sinha, staking claim to form an alternative government.

Apart from Shah, Union Health Minister J P Nadda and Union Minister Vijay Goel paid a visit to Parrikar. Earlier in the day, Shah flew to Delhi from Rajasthan and left again for the state after visiting AIIMS.

According to a hospital source, "Parrikar is not critical and is being treated by a team of doctors. He has not undergone any procedure so far." The sources had said on Sunday that the Goa chief minister underwent a series of tests at the premier health institute.

Parrikar was flown to the national capital owing to his declining health. He had returned from the US in the first week of September, days after which he was admitted to a hospital at Candolim in north Goa.

Earlier this year, he had undergone a three-month-long treatment in the US.

The BJP high command has sent three senior leaders -- Ram Lal, B L Santhosh and Vinay Puranik -- to meet the state party leaders and allies to take stock of the political situation after Parrikar was admitted to AIIMS.

The Congress, which has 16 members in the 40-member state Assembly, submitted a memorandum to the Governor, urging her not to dissolve the Assembly and instead invite the party to form the government, Leader of Opposition Chandrakant Kavlekar said.

The state is being ruled by the BJP-led alliance. The BJP has 14 seats in the Assembly, its allies Goa Forward Party and MGP have three each. Three Independents and an MLA from Nationalist Congress Party also support the BJP-led government.