The boss of HS2 has recommended reconsidering a controversial section of the route that would decimate parts of Camden Town as he challenged politicians to pave the way for faster building of the new high speed-line to reduce costs.

HS2 chairman Sir David Higgins, proposed a larger development at Euston - the projects southern terminus - but added that plans to link HS2 with HS1, the London to Kent Channel Tunnel high-speed rail link at St Pancras International, should be reconsidered.

Launching a report entitled HS2 Plus, Sir David, the former London Olympics guru, also called for a new look at ways of improving connections between phase two and the existing railway.

He also proposed an accelerated timetable for the northern section of a project, known as phase two, which is fiercely championed by some yet bitterly opposed by others.

Phase one of HS2 would see a line running from London through Tory heartlands to Birmingham and is due for completion in 2026.

Phase two will see the line continue in a Y-shape from Birmingham to north west and north east England and, under current plans, would be completed around 2032/33.

The current whole-line cost, including contingencies, is £42.6 billion, with £7.5 billion for the trains.

Shadow chancellor Ed Balls is concerned about the cost with other former Labour grandees expressing reservations about the scheme.

Shadow transport secretary Mary Creagh, however, welcomed today’s report saying: “As always we will continue to hold the government to account for keeping costs down on the project.”

Outlining his report in Manchester today, Sir David said reducing the contingencies, which have pushed the total cost of the project up, would be “irresponsible”.

But he said cost cuts might be possible later and he laid down the gauntlet to politicians by saying the speedier the HS2 legislation the better for cost reductions.

Sir David, formerly chief executive of Network Rail, said HS2 was “vital for the future of the country”.

He added: “The cost and impact have to be recognised and acknowledged, but so too do the cost and impact of doing nothing.

“Without HS2, the people of this country will continue to face the failures of our transport system on a daily basis.”

Sir David said the government should “accelerate phase two as soon as possible”.

This would take the line 43 miles further north than planned, to a new transport hub at Crewe in Cheshire which could be completed by 2027, six years earlier than planned.

Sir David said the Crewe option was good for the area and the north of England generally, while a “more comprehensive redvelopment” of Euston could see the station become “an iconic driver of local regeneration whose beneficial effects will be felt for generations”.

Sir David said that despite the potential benefits of HS2, he was “conscious of the price - financial, physical and emotional - that HS2 will demand from the country, from communities and from individuals”.

He went on: “That is why I have rejected any thought that the project should cut back on planned mitigation measures, whether noise or environmental. Those will continue.

“It is also why I support the government’s proposed approach to property compensation. We need to be clear about the impact of the project, as well as its benefits, and address the consequences of that impact, as we are.”

Legislation covering phase one is currently going through parliament and transport secretary Patrick McLoughlin has said that the legislation will not be completed before the general election.

Sir David said: “The uncertainty over the legislative timetable plus the inherent risks associated with any project at this early stage is why I have resisted the temptation to reduce the large contingency contained in the budget.

“The same approach should be taken to the second phase when the work outlined above is complete.”

But he added: “None of that is to rule out the possibility that a target for a lower budget for phase one could be set at some point in the future, but only when the legislative timetable becomes clearer and more certain.

“There is a direct connection between the length of time the parliamentary process takes, and the amount of contingency that is required.”

Sir David acknowledged: “HS2 is an enormous undertaking, but it is not an end in itself. If we do it right, it can be a catalyst for fundamental change at both a local and national level, up and down the country.

“It is ambitious because it needs to be, to meet the demands not just of the here and now, but of the future.”

Business Secretary Vince Cable expressed support for Sir David’s phase two plans while the Institution of Civil Engineers and the CBI were among other groups that received the report warmly.

However, anti-HS2 groups cast doubt on the possibility of bringing forward the phase 2 work while the revamped Euston plan was seen as merely bringing “more wealth and work into London”.