SKETCH TOM PETERKIN

The sight of Lib Dem leader Willie Rennie vigorously tearing up a piece of paper was one of the more unusual spectacles at First Minister’s Questions.

He wasn’t disposing of Lord Steel’s party membership card, as one wag suggested.

Rather, the drama was his way of telling Nicola Sturgeon to “rip up” the document the Scottish Government signed in support of a third Heathrow runway.

In 2016, the Scottish Government gave its support to the third runway by signing a “Memorandum of Understanding” with Heathrow.

The support was offered on the basis it would create thousands of jobs in Scotland.

That position became more difficult for Ms Sturgeon when she declared a climate emergency in April last year.

Since then Ms Sturgeon has said she would review the Scottish Government’s stance, but has stopped short of withdrawing support.

There had, she said yesterday, been “understandably and rightly” questions about whether Heathrow expansion chimed with tackling climate change.

“I am not sure how I can make my position any clearer,” she added, failing to add clarity.

It was then that Ms Sturgeon resorted to telling Mr Rennie that the Heathrow decision was not one for the Scottish Government.

“It is not within our power or areas of responsibility,” was the convenient get-out clause.

It will be wheeled out again when Scottish ministers are confronted by angry businesses who had hoped an extra runway would boost Scottish connectivity.