Congress MPs’ sit-in right at one of the entry gates to 7, Lok Kalyan Marg, Prime Minister Narendra Modi’s official residence, may have looked like a surprise to an unsuspecting eye but was well planned.Top party leaders, including Rahul Gandhi, Priyanka Vadra and KC Venugopal, accompanied by several Congress MPs, first reached the residence of party chief Mallikarjun Kharge’s at Rajaji Marg in central Delhi to celebrate the latter’s birthday as he turned 84.Soon thereafter, Gandhi, along with the Congress congregation, started marching towards the PM residence barely metres from Kharge’s house.In no time, a strong gathering of Congress MPs reached a key gate of the PM house and sat in a dharna right outside, virtually constituting what top Delhi cops described as a major security breach in the most security-sanitised area of the capital.A senior police official said that due to Kharge’s birthday there was already a massive rush in the area and several vehicles were parked along Rajaji Marg.The protest march by Congress MPs which lasted over three hours right at PM’s gate took the Delhi Police completely unawares, with questions being raised as to the vigil at India’s most secure location — 7 Lok Kalyan Marg.It remains to be seen whether Delhi Police are held accountable for what its own officials admit was a security breach.It is learnt that the police were expecting the Congress leaders to march to Vijay Chowk near Parliament.