"I cannot understand whether the Congress was running a government or the durbar of its own (Christian) Michel mama," he said at a Bharatiya Janata Party (BJP) rally here, referring to the alleged middleman in the AgustaWestland VVIP chopper scam, Christian Michel, who has recently been brought to India from Dubai.

The prime minister was addressing the rally after unveiling a slew of projects worth over Rs 4,500 crore in different sectors ahead of the general election.

This was Modi's second visit in less than a fortnight to Odisha, where the Assembly election is also slated to be held along with the Lok Sabha polls.

Mounting a scathing attack on the Congress after a showdown between the government and the Opposition in Parliament over the Rafale deal, Modi alleged that there was a conspiracy to weaken the country's defence forces during 2004-2014 (the period of the UPA rule) and the revelation of facts was now "paining" the opposition party's leaders.

"Therefore, they want to remove the chowkidar (watchman) from their path at any cost. Be it the society or factories, thieves always conspire to remove the chowkidar to make their task easy. As long as the chowkidar remains, they are unable to operate," he said, apparently slamming Congress chief Rahul Gandhi for his "chowkidar" barb at him.

"This also pains them because their secrecy is now coming to the fore," Modi said, adding that there were reports that a letter of Michel had revealed that he had close ties with top Congress leaders and ministers.

The middleman was aware of every movement of files in the PMO as well as the details of deliberations of the Cabinet Committee on Defence, he claimed, adding that Michel was also passing on crucial information related to defence, security and weapons procurement abroad.

"Perhaps middlemen had more information than the then prime minister himself," Modi said, while asserting that a thorough probe would be conducted into these matters.

"I want to make it clear that the role of people in protecting the interest of middlemen at the cost of the country will be thoroughly probed," he said.

Modi said the BJP government at the Centre had always taken hard decisions for the country's security.

"Those who have done injustice towards the armed forces should be booked.... I want to assure you that law will not allow anyone to go scot-free," he said.

Modi praised Defence Minister Nirmala Sitharaman for her skilful response in Lok Sabha on the Rafale issue on Friday, when it was raised by opposition parties.

"I congratulate the country's first woman defence minister for showing people the real face of those who deceive the country, those who compromise national security for politics and those who insult the sacred Parliament with their immaturity," he said.

Continuing with his attack, Modi said, "The leader of the country's oldest political party (Gandhi) has accused me of dividing the people of India by chanting Bharat Mata ki Jai."

He cited the instance of the newly-formed Congress government in Madhya Pradesh, which, after coming to power in the state, has discontinued the practice of the national song, "Vande Mataram", being played at the secretariat.

"Now, they are looking for a way out," the prime minister said, adding that the Madhya Pradesh government had also attempted to scrap the pension for those jailed during Emergency.

"This is an assault on democracy", he said.

Listing the achievements of the BJP-led National Democratic Alliance (NDA) government at the Centre, Modi said total immunisation of women and children, which had hitherto remained a distant dream, was fully achieved during the last four-and-a-half years.

The government had taken concrete steps for the empowerment of women, who were now doing "excellent work" in the Air Force and Navy, he said.

Six crore women belonging to all sections and categories were provided with LPG connections under the Centre's Ujjwala scheme in the last 32 months, Modi said, adding, "All the welfare schemes are being implemented in a balanced way to benefit all".

Earlier, the prime minister unveiled a digital plaque to mark the commencement of work for conservation and development of the Rasika Ray temple, and the excavated structure at the ancient fort of Haripurgarh.

He laid the foundation stones for three national highway projects, dedicated to the nation the Balasore-Haldia-Durgapur LPG pipeline of IOCL and inaugurated a multi-modal logistics park at Balasore and six passport sewa kendras.

He also flagged off the second passenger train from Tatanagar to Badampahar.

Modi told the gathering that the total worth of projects inaugurated was more than Rs 4,000 crore.

The Centre was focussing on infrastructure development, which would make a fundamental difference in the life of the common man, he said, adding that unprecedented investments were being made towards a modern infrastructure and connectivity in the country and the emphasis was on road, rail and air connectivity.

The middle class and the medium enterprises of the would get the maximum benefit of an enhanced infrastructure, the prime minister said, adding that modern roads, clean trains and economical air travel -- all contributed to the ease of living for the middle class.