Questions have been raised over the safety of Tottenham’s new stadium after the club announced it is to delay the opening of the £850m venue.

At least two Premier League games as well as a lucrative NFL fixture will now be played at Wembley this autumn after Spurs said they had found “issues” with critical safety systems at the new White Hart Lane. As the club pursue “urgent” meetings with the project’s contractor, there remains the possibility of further fixtures being moved. It is understood that Spurs have paid an undisclosed sum for the use of Wembley until the end of the year.

In a statement the club said: “Following the release of the Premier League fixtures for the 2018/19 season, we announced that, barring any significant issues with the final stages of stadium completion, our match against Liverpool on 15 September would be the first in our new stadium. Recent testing and commissioning has now shown issues with the critical safety systems. Urgent follow-up meetings with [the construction company] Mace and the trade contractors are now taking place.

Tottenham facing up to reality check as stadium costs escalate Read more

“The delays created by these difficulties mean test events need to be rescheduled to take place ahead of any first official match at the new stadium in order to achieve the safety licence. In the meantime, therefore, our upcoming Premier League matches against Liverpool and Cardiff City [6 October] will be switched to Wembley, as will the NFL match scheduled for 14 October.”

The sudden change of schedule is an embarrassment for Spurs, a week after they became the first Premier League club not to buy any players in the summer transfer window since its inception in 2003.

The Fiver: sign up and get our daily football email.

The NFL’s executive vice-president, Mark Walter, said he “totally understood the issues” that had led to the switching of games and said he remained “very excited about our long-term partnership with Tottenham Hotspur”.

“We know this will be disappointing for all our fans worldwide,” said the chairman, Daniel Levy. “We appreciate the support our partner the NFL has shown since the extent of this issue became evident today. At the start of the project we asked for your support during what we knew would be a complex and challenging build and now we ask for your continued patience and forbearance.”

Dele Alli gets Tottenham off to a winning start against Newcastle Read more

Spurs have been pursuing an ambitious schedule for their new ground, which is being built on the same site as the old White Hart Lane. In June they announced that they had agreed to delay their opening home game of the season in order to allow completion of the project. Subsequently Spurs said they would play the coming Saturday’s fixture against Fulham at Wembley.

This week the club are thought to have activated a clause in their agreement with Wembley, where they played their games last season and which allows them to arrange further fixtures until the end of 2018.