The Supreme Court on Tuesday allowed double lane widening for the strategic Chardham highway project in Uttarakhand, saying the recent past has thrown serious challenges to national security.

The court in the exercise of judicial review cannot second guess the infrastructural needs of the armed forces, the bench headed by Justice D Y Chandrachud said while also setting up an oversight committee headed by former Justice A K Sikri to report to it directly on the project.

The strategic 900-km Chardham project worth Rs 12,000 crore aims to provide all-weather connectivity to four holy towns -- Yamunotri, Gangotri, Kedarnath and Badrinath.

In its judgment, the bench, also comprising Justices Surya Kant and Vikram Nath, clarified that the oversight committee will not undertake a fresh environment assessment.

The committee will receive all support from the ministries of Defence and Road Transport, the Uttarakhand Government and all district magistrates.

The top court said that there are no malafides in the application filed by the Defence ministry. The allegation that its application seeks to relitigate matters or to subvert previous orders of this court are unfounded.

As a specialised body of the government, the Defence ministry is entitled to decide operational requirements of the armed forces, including infrastructural support needed for facilitating movement of troops, it said.

"The bonafides of MoD are also evident from the fact that the issue of security concerns was raised during the discussion of HPC and finds mention in HPC report. This MoD has maintained the need for double lane roads for border security concerns.

"The appellants have referred to a statement made by Chief of Army Staff in 2019 in a media interview regarding the adequacy of infrastructure for troop movement. We do not find it necessary to place reliance on statements made to the media given the consistent stand of MOD. The security concerns as assessed by MoD may change overtime. The recent past has thrown serious challenges to national security," the bench said.

The apex court said the armed forces cannot be held down to a statement made during a media interview in 2019 as if it was a decree written in stone.

"This court in the exercise of judicial review cannot second guess the infrastructural needs of the armed forces. The submission of the appellants requires the court to interrogate the policy choice of the establishment which is entrusted by law to the defence of the nation. This is impermissible," it said.

If the Army cannot move its missile launchers, heavy machinery up to the northern Indo-China border, then how will it defend it and fight a war if it breaks out, the Centre had said in a poser to the apex court earlier.

Trying to allay the concerns of landslides in Himalayan regions due to the construction of the wider Chardham highway project, the government had said all necessary steps have been taken to mitigate the disaster. It added that landslides have happened in various parts of the country and not specifically due to road construction.

The court was hearing the Centre's plea seeking modification of the September 8, 2020 order, which had asked the Ministry of Road Transport and Highways to follow the 2018 circular stipulating a carriageway width of 5.5 metre on the ambitious highway project which goes up to the border with China.

In its application, the MoD had said it seeks modification of the order and directions that the national highways from Rishikesh to Mana, from Rishikesh to Gangotri, and from Tanakpur to Pithoragarh may be developed to two-lane configuration.