Image caption Lord Purvis said the current 'piecemeal' approach to devolution was not working

Scottish Liberal Democrat peer Jeremy Purvis has set out plans for a new constitutional convention for the UK.

Lord Purvis said he wanted an end to the current "make do and mend" approach to constitutional reform that could "threaten the UK".

His proposal contains plans for further devolution to each of the home nations and local authorities.

It also suggests ways of reforming the Westminster voting system and the House of Lords.

The peer presented his Constitutional Convention Bill in the House of Lords on Monday. He said it aimed to deliver a "sustainable, balanced devolution settlement that works for the whole UK."

His proposals would see a year-long convention comprised of politicians from all political parties and representatives from wider civic society.

More powers

Scotland is due to receive new powers over tax next year when the Scotland Bill comes into effect.

However, following its landslide victory in the general election, the SNP has been pressing the UK government for further powers over employment and welfare policy.

The SNP's general election manifesto said it was in favour of so-called full fiscal autonomy - power over all tax and spending - but that this would take time to deliver.

Meanwhile, Tory MP Ian Stewart told the BBC on Sunday that his party was open to constitutional reform for the rest of the UK.

Plans to give MPs from English constituencies an effective veto on laws affecting only England were included in last week's Queen's Speech.

Lord Purvis welcomed the new powers package for Scotland but said "piecemeal devolution" could not deliver stability.

'Secure the future'

He added: "Pitting one part of the UK against another is no way to secure the future of our country.

"We need to abolish the make do and mend approach to reform that has let the SNP move the devolution goalposts time and again in a way that might work for them, but not for Scotland or the rest of the UK.

"A constitutional convention will help us reach a settlement that protects the future of the UK and delivers communities the powers they need to thrive."

Lord Purvis also said it was time to "grasp the nettle" and tackle reform of the electoral system and the House of Lords.