There are sound reasons to oppose a 'love tax' – once again the Lords is our best protection

The Lords acted decisively in defence of the low paid late last year by obstructing tax credit cuts

Peers are being urged to block welfare reforms that will impose a 'love tax' of around £1,000 on single parents who get married or find a new partner (AFP/Getty)

The background to stories of conflict between the two Houses of Parliament has changed during our lifetime. A generation ago, unelected members of the Upper House were notorious for streaming into London from their country seats to vote in vast numbers in favour of reactionary measures like the notorious poll tax, from which they stood to gain handsomely.

But in the past two decades, the make-up of the Lords has changed radically. The permanent Conservative majority disappeared when hereditary peers lost their automatic voting rights. Now the Tories are heavily outnumbered by Labour and the Liberal Democrats, whose numbers are way out of proportion to the votes they received in the last general election.

Far from placing the defence of landed interests at the top of their agenda, the Lords acted decisively in defence of the low paid late last year by obstructing George Osborne’s planned assault on tax credits. This so angered Conservative ministers, who believed that unelected peers had no business interfering with a measure involving public money, that they launched a review to see if it could be prevented from happening again.

With that threat hanging over them, it would be understandable if the mood in the Lords is nervous on Wednesday. The issue before them is the so-called “love tax”. Single parents receiving Universal Credit, the new system of welfare support expected to be introduced in 2017, may discover that finding love and moving in with a new partner sets them back by up to £1,080 a year in lost benefits, according to research carried out for the Liberal Democrats.

The number of households affected could be high. About half of all single parents find a new partner within five years of the break-up of their previous relationship, indicating that the cuts could hit half a million people. While this is an attractive potential money saver from the Treasury’s viewpoint, it does not sit well alongside a Government promise that no one who is moved from the current system of welfare benefits on to Universal Credit will be any worse off. Universal Credit, the brainchild of the Work and Pension Secretary, Iain Duncan Smith, is not supposed to save money; it is intended to enable those who want to get off benefits and into work to do so without losing out.

The Liberal Democrat leader, Tim Farron, has also made the point that the Conservatives believe it is generally better for a child to be raised in a two-parent household, yet they propose to inflict a heavy penalty on a single parent who forms a new relationship. Additionally, it looks rather contrary to interfere with the private affairs and finances of individual citizens in the same week that it became known that large corporations including Google have been allowed a certain freedom with their own.

There is therefore a good argument for the Lords to force the Government to think again. But of course, if they do, they will again be open to the accusation that the unelected chamber is frustrating the will of the elected Commons on a matter involving money.

The present constitutional set-up is hardly ideal. There are strong arguments for and against getting rid of the House of Lords and replacing it with an elected upper chamber, yet the system for electing MPs is not ideal either. A political party that received 37 per cent of the vote in last year’s general election now has a complete grip over the Commons.

The only body capable of blocking bad legislation after it has been through the Commons is the House of Lords. They should use that power when they believe it is right – and if the Conservatives do not like it, let them change the system and introduce an elected upper chamber.