NEW DELHI, Jan. 12 (Xinhua) -- Two major political parties and arch rivals Samajwadi Party (SP) and Bahujan Samaj Party (BSP) on Saturday formally announced their pre-poll alliance in northern state of Uttar Pradesh for the upcoming Indian general elections.

Leaders of the two parties, Akhilesh Yadav of SP and Mayawati of BSP addressed a joint press conference in Lucknow, the capital city of Uttar Pradesh, and thus delivered the first opposition front to take on the ruling Bharatiya Janata Party (BJP) led by Prime Minister Narendra Modi.

"This press conference will give Prime Minister Narendra Modi and BJP president Amit Shah sleepless nights," Mayawati said.

"We will contest 2019 election in alliance. This will be a new political revolution. We have buried the hatchet and decided to come together," Mayawati added.

Announcing their tie-up for general elections, both parties have agreed to fight on 38 seats each, out of 80 seats.