A complaint by former Cabinet minister Priti Patel that Remain campaigners colluded to flout spending rules in EU referendum has been rejected by the official elections watchdog.

The Electoral Commission said it did not have “reasonable grounds” to believe the official Britain Stronger in Europe (BSiE) group exceeded its spending limits and would not be opening an investigation.

The ruling followed a complaint by Ms Patel, the former international development secretary,  that BSiE failed to report joint spending with Labour, the Liberal Democrats and the Conservatives IN campaign.

In her evidence, Ms Patel cited two books published since the referendum – including one by David Cameron’s former communications chief Sir Craig Oliver – describing daily telephone meetings of Remain campaigners chaired by BSiE.

In a letter to Ms Patel, the commission’s head of regulation Louise Edwards said: “Following examination we are satisfied that while liaison took place there is no evidence of joint spending as a result.

“The evidence indicates that the meetings were advisory in nature, focussed on communications and did not involve or result in decisions on referendum spending, or the coordination of campaign activities across campaigners, as part of a common plan or other arrangement.

“We are also satisfied that any instances of working together resulting in referendum spending between BSiE and other campaigners, including spending associated with the coordination of volunteers by BSiE, has been reported.”

A BSiE spokesman welcomed the finding saying they had always been confident that they had acted within the rules.

“We have always taken our legal responsibilities seriously and so are very pleased that the Electoral Commission have ruled out opening an investigation,” the spokesman said.