Kolkata's Brigade Parade Ground is all set to host Trinamool chief Mamata Banerjee's mega rally for a grand alliance of opposition parties this noon, with political leaders from all corners of the country joining in. Among the first to make an appearance were Samajwadi Party leader Akhilesh Yadav, DMK chief MK Stalin, former BJP leader Arun Shourie, Loktantrik Janata Dal chief Sharad Yadav and Nationalist Congress Party head Sharad Pawar. At least 25 top political leaders are expected to occupy the stage at the event -- called the "United India Rally" -- aimed at uniting various political parties against the Narendra Modi-led BJP in the upcoming Lok Sabha elections. Ms Banerjee, also the Bengal chief minister, spent several hours on Friday interacting with visiting political leaders put up at various hotels across the city.