he Conservative party is far from the margin of British politics, but it has yet to recover the relevance to which it feels historically entitled. The Tories are flattered by their status as the official opposition in parliament. In the wider country, Reform UK has set the agenda on the right, overtaking Kemi Badenoch's party in opinion polls and poaching MPs from her benches.

But Nigel Farage's progress has stalled. Scrutiny of Reform's finances has made its leader look shifty. Competition from Restore Britain, an extreme nationalist party, has denied Mr Farage the luxury of taking far-right votes for granted. Pandering to a hardcore audience makes it difficult for Reform to affect the moderation required to capture more Tory and Labour votes.

This creates an opportunity for Conservatives to reassert themselves as the mainstream opposition to Labour. Many Tories believe the available space has grown since Andy Burnham replaced Sir Keir Starmer as prime minister.

Mr Burnham has a bolder agenda than his predecessor, and he communicates it well – qualities that have been rewarded with a poll-ratings recovery. It is also a programme with unapologetic left-liberal ambition – universal social care, free at the point of use; opening the door to public ownership of utilities; dissolving red lines in relations with the EU; electoral reform. Under new leadership, the party has risen out of the defensive crouch from which it fought the election, fearful of offending Conservative sensibilities. Conservatives are duly offended. The vision that Mr Burnham outlined at his party conference last week was a repudiation of Margaret Thatcher's legacy, and there is no greater heresy in Tory doctrine.

Mrs Badenoch will not struggle to articulate a rebuttal at her party's conference in Birmingham over the next few days. She is a devotee of the Conservative cult of the Iron Lady, committed to low taxes and a smaller state as axioms of political virtue. She believes there are voters who share that conviction, who will be repelled by Labour, and who are deeply wary of Mr Farage. This is the electoral audience she is targeting.

It isn't an irrational strategy, but nor is it a well-developed one. Mrs Badenoch likes to debate the opponent she wants rather than the one she has. She accuses Mr Burnham of taking Britain back to the 1970s, without engaging with his analysis of what went wrong in the 1980s or considering that her own nostalgic ideology might need revision with reference to subsequent decades.

Her approach to Reform is even more blinkered. The Tories want voters to take a dim view of Mr Farage's candidacy to be prime minister, but they are selective in their criticism. Mrs Badenoch joins the fray over opaque donations, but has less to say about Reform's toxic rhetoric around immigration, largely because Conservative policy fits the Faragist mould. The traffic in defections has slowed, but the boundary between the two parties is porous.

To make her party competitive in British politics, Mrs Badenoch needs more serious arguments. She needs an answer to Mr Burnham that doesn't retreat into lazy 20th-century political cliche. And she needs to reject Mr Farage's brand of national populism in terms that give voters reasons to distinguish between their two parties on points of principle, when at the moment there are none.