Uttar Pradesh powerhouses Akhilesh Yadav and Mayawati, bitter rival turned partners-in-polls, today announced their long-anticipated alliance to take on the ruling BJP in the national election due by May, declaring that it would give Prime Minister Narendra Modi and Amit Shah "sleepless nights". The Congress will not be a part of the alliance, they said, saying there was no "real gain" from any tie-up with Rahul Gandhi's party.