At 0743 GMT, Taylor Wimpey, Persimmon and Berkeley were all down 1.3% and 1.6%, lagging the broader FTSE 100 index, which was up 0.2%.

"Help to Buy was originally intended as a short-lived scheme, but will now last for 10 years and consume over 8 times its original budget, yet the value achieved from its extension is uncertain," the House of Commons' Public Accounts Committee (PAC) said in a report published on Tuesday.

Without alternative housing initiatives, the ending of the project in 2023 may lead to a fall in supply adding to the challenge it already faces in achieving its ambition of 300,000 homes a year from the mid-2020s, it cautioned.

"The new scheme from 2021 provides an opportunity to target the money more effectively, but (the Ministry of Housing, Communities & Local Government) has not yet fully thought out how it will do this," it said.

Britain's PAC, which is charged with monitoring government financial affairs, does not have any formal powers to change policies they disagree with.

To see the full report: https://bit.ly/2mkt765

(Reporting by Josephine Mason; additional reporting by Kate Holton; Editing by Thyagaraju Adinarayan)