Attacking the Opposition plans for a grand alliance to checkmate BJP and Prime Minister Narendra Modi in the 2019 Lok Sabha polls, Home Minister Rajnath Singh on Friday said politics should be done for development of the country not to stop anyone."Opposition is trying to form a grand alliance to come to power. Their single agenda is to defeat BJP and Modi. But, in my view, politics should be done for development of the country, not to stop anyone," he said at the 16th Hindustan Times Leadership Summit.Asked about Bahujan Samaj Party chief Mayawati's statement ruling out alliance with Congress in the Assembly elections, Singh said only "behenji" can answer that.The senior leader also said there is a crisis of credibility that India has been facing and that the Modi government has accepted that crisis as a challenge. "We will neither let it deepen nor allow it to worsen."He rejected as baseless the allegation that the Centre was trying to create hurdles to the AAP government in Delhi.The Home Minister, however, said those who are running the Delhi government should at least think that it was not a full-fledged state.Asked about getting fugitive 1993 Mumbai serial blast mastermind and underworld don Dawood Ibrahim back to India, he acknowledged that "there were difficulties in bringing him back".