HS2 will not be extended to Euston unless enough private investment is secured, it has been reported. While cancelling HS2 to Manchester this week, Rishi Sunak pledged to extend the high-speed railway to the central London station. But PA Media, citing a No 10 source, reported the promise was contingent on a substantial proportion of the cost being met by private funds. If not enough money is found, HS2 will permanently stop at Old Oak Common in the capital’s western suburbs. Extending HS2 to Euston involves digging a 4.5-mile tunnel from Old Oak Common and building a six-platform station next to the existing west coast mainline terminus. At his speech to the Conservative party conference on Wednesday, the prime minister said: “We will complete the line from Birmingham to Euston.” In the Network North prospectus released after the speech, the Department for Transport (DfT) said the Euston project would “take on the lessons of success stories such as Battersea power station and Nine Elms, which secured £9bn of private sector investment and thousands of homes [in London].” It went on to say that to ensure “best possible value for the British taxpayer” the government would ensure that “funding is underpinned by contributions from those people and businesses its development supports”. DfT officials believe the capacity of Old Oak Common as a terminus station can be stretched to eight trains an hour, which is the same as planned for Euston after the scrapping of HS2 north of Birmingham. But there are concerns at the comparative lack of options for onward journeys from Old Oak Common. Government modelling shows two-thirds of people would prefer to travel to or from Euston. HS2 work at Euston was paused in February because costs had ballooned to £4.8bn compared with an initial budget of £2.6bn. The DfT said it would appoint a development company, separate from HS2 Ltd, to manage the delivery of the Euston project. Euston was initially due to have 11 platforms for high-speed trains but will now have six. A new HS2 station at Manchester airport – which will now not be built – was always contingent on “third-party funding”, something the Greater Manchester mayor, Andy Burnham, always said was unfair. Before the cancellation of the northern leg this week, Burnham often questioned why northern businesses were being asked to chip in for the airport station, when London firms were not asked to do the same for Euston. Now, it seems, they are. The DfT has been approached for comment.