MP Caroline Lucas says praising a young climate activist is not enough and urgent action is needed.

Ms Lucas, Green MP for Brighton Pavilion, spoke after a meeting with Greta Thunberg, 16.

She sat next to the Swedish activist as she spoke to MPs in the House of Commons, saying her generation “probably didn’t have a future any more”.

The teenager, who has inspired schoolchildren across the UK to hold climate change marches, said: “You lied to us. You gave us false hope. You told us that the future was something to look forward to.

“And the saddest thing is that most children are not even aware of the fate that awaits us. We will not understand it until it’s too late.

“Many of you appear concerned that we are wasting valuable lesson time but I assure you we will go back to school the moment you start listening to science and give us a future.”

Ms Lucas spoke highly of the teenager, praising her “honesty and directness”.

The MP later talked with opposition leaders in an “unprecedented meeting” with environmentalists including Greta.

Ms Lucas said: “Greta has had a huge impact, thanks to her honesty and directness.

“She spoke to a packed room and challenged all those MPs listening to her speech to act in accordance with what the climate science requires, not just with what they perceive to be ‘politically possible’.

“And she urged the Government to tell the truth – to stop using dodgy emission reduction figures that make it look as though the UK has made much more progress than we have, because those figures fail to incorporate emissions from aviation, shipping and imports.”

The meeting prompted Environment Secretary Michael Gove to say the Government wasn’t doing “nearly enough” to address global warming.

But Ms Lucas warned “warm words” would not solve the issue, only urgent action.

She said: “Greta’s visit also led to an almost unprecedented meeting of opposition party leaders who agreed to work together on some concrete next steps.

“She made it clear that warm words are not enough –we need to see an urgent step change in action and ambition.

“Keeping our environment high on the political and public agenda is therefore critical and I and many others will be doing what we can to do just that.”

After the meeting, Ms Lucas blasted clean energy minister Claire Perry in Parliament for asking what a climate emergency looked like.

The Green MP said it looked like what was “scientifically necessary”, including ensuring all election commitments do not encourage further greenhouse gas emissions.

She said: “In the meeting this morning that unfortunately the Prime Minister couldn’t make, we agreed to a number of proposals. Will her Government sign up to those?”

When Conservative MP Ms Perry said the UK “led the world” in cutting emissions, Mrs Lucas shook her head and said “It’s not true.”