Naming a number of senior UPA ministers, Modi in a series of tweets claimed his disclosures, which he termed as "bombshells", would implicate the "erstwhile PMO".
"Congress party should be watching this press conference. So should all who have jumped up and down in last few years," he said in a tweet.
"Lastly before I board another flight to another beautiful destination. This is war. So bring it on. I choose to lose a battle to win a war," a combative Modi, who is based in London, said in another tweet.
"Now finally it's my turn to get EVERYTHING OUT. THERE ARE MANY BOMBSHELLS. See for yourselves. Then judge," he said.
He also asked the UK government to look out for his disclosures "As there is lots of Q u will have to answer to media I can assure u."
He warned of disclosing "Secret emails between govts exchanged. Lying to courts".