Boris Johnson faces calls to go "further and faster" in fast-tracking new laws to clamp down on Russian oligarchs in the UK.
The Government has already taken steps to toughen UK sanctions after widespread criticism that it had been slower to act than the EU and US.
Ministers agreed that changes will be made to the Economic Crime Bill on Monday to allow the UK to impose sanctions on anybody who has already been targeted by Western allies.
They will also remove some of the constraints preventing groups of individuals, for example Russian MPs who backed the Ukraine invasion, from facing swift action.
Some human rights protections that have until now shielded oligarchs with interests in the UK from sanctions will also be lifted.
Home Secretary Priti Patel said the new law would make sure there was "sound legal footing" for the Government to "go after" oligarchs.
But Labour leader Keir Starmer said there was a "bit of frustration" as the issues holding back the UK from acting faster against Kremlin-linked figures were not new.
"Yes, we support what the Government is doing, but we do think they could go further and faster, and we are going to be pushing them to do that tomorrow on that issue," he added.
Labour hopes to amend the Economic Crime Bill to reduce the time required to register foreign-owned property to just 28 days to prevent it being sold off.
Ministers have already proposed reducing the time given to comply from 18 months down to six but the Opposition said this would give oligarchs a "get out of jail free" card.
The new law is designed, in part, to try and help tackle the swathes of Russian money thought to be in the UK.
The money is often buried in property, with the true owners hidden behind shell companies that only exist on paper, sometimes registered in offshore tax havens.
Cross-party MPs, led by ex-Cabinet minister David Davis, are also pushing for tougher measures with oligarchs stripped of UK assets seized even before the British authorities have completed formal steps to impose sanctions.
This would mean land, houses, flats, businesses, yachts or boats and aircraft, could be seized without delay.
The cross-party group of MPs that supports the move - which would be the toughest action yet - will meet to discuss tactics before the Commons debate.
They include senior Labour MPs, including Chris Bryant and Kevan Jones, as well as the Lib Dems Layla Moran and former Tory cabinet minister Andrew Mitchell.
Mayor of London Sadiq Khan, while not an MP, agreed ministers should immediately move to seize assets including jewellery, designer clothes, cars and property - and sell them to fund aid to Ukraine.
City Hall warned it must happen now before oligarchs have the chance to preside over a “firesale” of assets to get ahead of sanctions.
Mr Khan said: “Nobody expected sanctioning President Putin’s allies in the UK to be straight forward, these are some of the richest and most powerful people in the world.
“But it is completely unacceptable that ministers are offering them such easy loopholes to disguise or liquidate their assets before the state can act.
“London can no longer be a laundromat for oligarchs’ finances. We know there is at least £1.1bn of property in London linked to the Kremlin, along with millions of pounds worth of art, cars, boats and other goods. Meanwhile, Ukraine calls for aid as the Russian army advances on Kyiv.
“We need the powers and political will to turn the ill-gotten gains of Putin-allies into Ukrainian aid. Ministers must not delay whilst Ukraine burns.”
