The sale of collapsed energy company Bulb has been delayed by a High Court judge after concerns were raised by rival firms.

The business is set to be bought by Octopus Energy, who announced it would be taking on Bulb's 1.5 million customers after the company was placed into special administration last year.

The deal aims to "protect consumers and taxpayers" and "provide a stable new home for Bulb's customers and 650 employees", the Department for Business, Energy & Industrial Strategy (BEIS) confirmed.

However, despite the BEIS saying the sale will be completed following a statutory process called an energy transfer scheme and Energy Secretary Grant Shapps giving the plan his approval, the date of when it will take place has now been pushed back.

High Court Judge Mr Justice Zacaroli ordered for the transfer date to be delayed from 15 November, saying energy companies Scottish Power, British Gas and Eon had raised concerns about the proposal.

British Gas and Scottish Power have argued they have not been given enough time to consider the deal, and raised the potential for a legal challenge against Mr Shapps' approval.

Bulb's administrators said there was "significant commercial urgency to justify going ahead" but a representative for British Gas said there were concerns the proposal could be "unlawful".

David Allison KC, for Scottish Power, later said there were "very serious concerns about the process".

He told the court: "There is such a degree of redactions to the terms of the deal, it is impossible for Scottish Power and its legal team to understand the agreement."

The High Court judge adjourned ordering the start of the scheme, with a hearing now expected around the end of the month.

Mr Justice Zacaroli said: "I do not think there is a level of urgency that requires me to go ahead and appoint an effective date today.

Friday's hearing comes after a different judge delayed a bid by Bulb's administrators for repayment of costs totalling more than £28m.