Modi belongs to the same political party as the premier
Chief Minister Narendra Modi arrived in Delhi as Hindu-Muslim clashes continued in Gujarat, just days before a proposed visit by Mr Vajpayee - his first since the riots began in February.
More than 700 people have been killed in the violence and Mr Modi's administration has been severely criticised by opposition parties as well as India's human rights commission for failing to contain the bloodshed.
The violence has spilled into neighbouring Maharashtra state, where seven people are now reported to have died
Officials in the main city of Ahmedabad said 50 buildings were set ablaze during street clashes between Hindu and Muslim groups on Sunday.
At least nine people have been killed in the state since Saturday.
Curfews are in force in several areas and paramilitary police are patrolling the streets.
In Maharashtra, the authorities have ordered a judicial inquiry into religious clashes in the town of Akola over the weekend.
The violence broke out during the Hindu religious festival of Holi, prompting the police to open fire in the town, some 300 kilometres east of the state capital Bombay.
Modi under fire
Mr Modi, who belongs to the prime minister's Hindu nationalist Bharatiya Janata Party (BJP), has faced widespread calls for his resignation.
Opposition politicians have alleged the state government did little to stop Hindu gangs from destroying Muslim property and mosques in what some say was clearly a pre-planned operation.
Mr Modi has denied the allegations.
On Saturday, he told investors in Bombay that Gujarat, one of the most prosperous Indian states, was fast returning to normal.