The government is set to announce that construction of certain sections of HS2 will be delayed to save money, the BBC understands.
It is thought the delay will primarily affect sections from Manchester to Crewe and Birmingham to Crewe.
But sources have also indicated that some of the design teams working on the Euston end of the line may be affected.
Contractors are looking at whether they need to redeploy staff working on that site.
The high-speed railway will link London, the Midlands and North of England.
However, it has been beset by delays and cost increases. In 2010, it was estimated to cost around £33bn but that has since swollen to at least £71bn.
Mark Thurston, chief executive of HS2 Ltd,
recently told the BBC that he and the government were examining the phasing of the build and the timing.
The project is grappling with the rising cost of materials due to the high rate of inflation.
It is understood that the government hopes that the delays will allow it to spread the cost over a longer period of time, making it more affordable by reducing annual expenditure.
Chancellor Jeremy Hunt, who will outline his Budget next week, wants debt to fall as a percentage of GDP within five years - a target explicitly set by the Prime Minister
Last week, Mr Thurston said the impact of inflation had been "significant" in the past year, "whether that's in timber, steel, aggregates for all the concrete we need to use to build the job, labour, all our energy costs, fuel".
He said HS2 was working with suppliers and the government to find ways of mitigating rising costs.
"We're looking at the timing of the project, the phasing of the project, we're looking at where we can use our supply chain to secure a lot of those things that are costing us more through inflation," he said.
Government blames soaring construction prices but says it is "committed" to the high speed rail link.
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