Financial professionals aren't impressed, judging by the performance of the FTSE 100 index and more worryingly, UK bond yields.

The FTSE index of top UK-listed blue-chip companies plunged more than 1% today, as it continued yesterday’s sell-off.

Investors aren't happy with Reeves for loading £25billion worth of tax hikes onto British businesses. Bosses will cut wages, shed jobs and reduce investment to survive. This will batter the economy.

The UK will survive a spot of stock market volatility. Share prices go up and down all the time. They're affected by a host of factors, and not just the Budget.

There's the small matter of a US presidential election next Tuesday, for example. Investors will soon be fretting about that instead.

Now here's what I am worried about.

The bond market hates the Budget too, and it's getting more suspicious by the minute. It's got an awful lot of power to harm the UK, as short-lived Tory PM Liz Truss discovered.

Most people never give the bond market a moment thought. Yet it's bigger than all the world's stock markets combined.

It's made up of big institutional investors, who want to invest huge sums money in low-risk, income-paying assets, primarily government bonds.

UK government bonds, known as gilt-edged securities or gilts, should be some of the lowest risk of all. Not anymore.

As we saw under Liz Truss, if bond investors think the UK government has lost grip of our finances, they demand extra interest for lending to us.

That means the national debt suddenly costs billions of pounds more to service every year. Or maybe tens of billions.

It's why mortgage rates shot past 6% after Truss’s mini-Budget fiasco in September 2022. She was gone within days.

The bond market finished her. The trigger was interest rates on 10-year gilts rocketing from 3.03% to 4.42% in just over a month.

This afternoon, gilt yields hit 4.5%. That's higher than under Truss. The so-called "bond vigilantes" are back in force and this time they're gunning for Rachel Reeves.

Yesterday, the Chancellor announced £40billion of tax hikes plus a further £32 billion of additional state spending. In total, she will borrow a staggering £300billion in the year to March.

All this borrowing will slow economic growth. By 2027, for example, the UK economy will grow by just 1.5%.

At that pace, our budget deficit and national debt are going to rise and rise. No wonder the bond vigilantes are waving their pitchforks.

They're not having it.

So far Reeves has survived higher bond yields than Liz Truss because interest rates are higher generally.

But Kathleen Brooks, analyst at XTB UK, said the danger is clear. "The Budget has caused a bond market reaction, and the bond vigilantes are back baying at the UK’s door."

The "sense of panic" around this Budget is akin to the Liz Truss meltdown, Brooks said.

She then asked the question everyone is asking: “How high will UK yields go? Now they have breached the 4.5% level, what is to stop them surging further?”

What has Reeves done? We'll find out in the coming days.