Keir Starmer mocked the new Tory leader Kemi Badenoch in their first head-to-head at PMQs.
Fresh from celebrating her victory in the bitter contest to replace Rishi Sunak, Ms Badenoch appeared to read from her pre-prepared lines as she attacked the government's "cruel family farms tax" over a change to inheritance tax rules at last week's Budget.
Moments before she had claimed that the PM's "scripted lines are showing that he has not even listened to the Budget himself".
But Mr Starmer responded: "I'm happy to help the leader of the opposition. If she's going to complain about scripted answers, it's probably best not to read that from a script.
I'm glad she's raised farmers. Because the budget last week put £5 billion over the next two years into farming. That's the single biggest increase, unlike the £300 million which was underspent under the last government. But when it comes to inheritance, the vast vast majority of farmers will be unaffected, as she well knows; as they well know."
Ms Badenoch also used her first PMQs session to launch a misleading attack on the Government over defence spending. She told MPs there was nothing in last week's Budget on defence spending.
In fact Chancellor Rachel Reeves announced an additional £2.9billion for the Ministry of Defence and said the Government would "set a path" to spending 2.5% of GDP on defending the country.
Ms Badenoch told the Commons: "His Chancellor's Budget did not even mention defence. The Chancellor's budget last week was a copy and paste of Bidenomics. It turns out that a high spending, high borrowing, high inflation approach is less popular than she may have thought."
The PM shot back: "The one thing I learned as leader of the opposition, it is a good idea to listen to what the Government is actually saying. I think she said defence wasn't mentioned in the Budget.
"It was seven days ago and it is absolutely clear and central to the Budget." He said that the Government is committed to bringing defence spending to 2.5% - and pointed out that the last time this was achieved was under the last Labour government.