George Osborne has been accused of “unspeakable” bullying over tax credit cuts by a peer.
Crossbencher Baroness Meacher complained at the way she and others were treated over proposed "fatal" amendments that would kill off the policy to cut tax credits, the Press Association reported.
She told BBC Radio 4's Week in Westminster: "There has been enormous pressure coming from the Treasury, the Chancellor of the Exchequer, upon peers.
"The weight on me has been unspeakable really. I think it’s bullying tactics."
Threats included that he would "close the House of Lords, that he will create 100 new Conservative peers", she added.
The Chancellor is under mounting pressure to mitigate the effect of the policy, with opposition parties and rebel Tory MPs threatening defeats in the Lords and Commons next week.
Threats to throw out the £4.4 billion cuts sparked warnings from David Cameron that peers should obey the convention that the House of Lords does not block financial policies approved by MPs.
The Prime Minister pointedly failed to rule out appointing hundreds of new Conservative peers to give the party a majority in the second chamber.
Osborne insisted this week he was "comfortable" with the policy despite analysis by the independent Institute for Fiscal Studies (IFS) that the introduction of a higher minimum wage will not offset poor households' immediate losses.
The IFS calculates that millions of people will lose up to £1,300 a year from the Budget changes.
But with the Lords set to make its opposition known - perhaps via a Church of England bishops' motion decrying the failure to take into account the short-term impact - and senior Tory MPs leading a rebellion in a vote in the Commons later in the week, there are reports concessions may be made.
Last week Labour narrowly lost a vote calling on the Government to scrap the cuts but despite a number of Conservatives, including Plymouth MP Johnny Mercer and South Cambridgeshire MP Heidi Allen, speaking out against the proposals, no Tories voted with Labour.
The motion was defeated by 317 voted to 295, giving a majority of 22 to the Tories.
The Treasury has given no hint that it will water down the cuts, claiming the £4billion in savings which it will deliver is needed to reduce the spending deficit.