With £20k to spare I could load up on cheap UK shares today in an attempt to retire early

I've spent the last year buying low-cost UK shares in a self-invested personal pension (SIPP) with one goal in mind. I want the freedom to retire early and I think building a portfolio of blue-chip stocks is the best way to achieve it.

I'm not saying that I'm actually going to retire early, because I love what I do for a living. I just want it to be something that can happen, say, if I'm sick, burned out, or want to take things easy.

If I had £20,000 to spare (I wish!) I wouldn't stay. I was going shopping FTSE 100 sharing right now.

I buy FTSE 100 bargains

Timing is important for three reasons. First, when I start investing, my money should grow over a long period of time.

Second, now looks like an excellent time to buy FTSE 100 shares at affordable prices, before the next stock market bull run begins.

Finally, I think a bull run is imminent, as interest rates fall and international investors wake up to opportunity in the UK. Global fund managers are now overweight UK shares for the first time since July 2021, according to Bank of America Global Fund Manager.

I think it's an FTSE 100 bank NatWest Group (LSE: NWG) is a good example of the value offered by UK shares.

Big banks have fallen out of favor since the 2008 financial crisis, but now they're gearing up for a recovery.

That NatWest share price is up 43.28% over the past year. It doesn't look cheap though, trading at 6.87 times earnings. The average FTSE 100 stock is worth more than double, trading at 15 times earnings.

Even better, NatWest provides opportunities for ongoing dividend income. Today, the stock has a trailing yield of 4.92%. That is forecast to rise to 5.41% next year, and then to 5.58% the following year. Fortunately, that's just the beginning.

High and rising income

With stocks, nothing is guaranteed. NatWest still needs to continue to generate more cash, to fund shareholder payments. Net interest margins – the difference between what banks pay to savers and charge borrowers – are likely to fall when the Bank of England cuts rates. That can squeeze profits.

However I still believe that in the long term NatWest should deliver a balanced mix of income and growth.

I wouldn't put my entire £20,000 in one stock, far from it. I would split investing in five different stocks, putting £4k into one.

Off the top of my head, I might add NatWest for insurance Avivaits shares yielded a bumper 6.81%. I might add a power network National Gridyielding 5.28%. Both seem reasonably priced.

The consumer goods giant Unilever returning to form after a difficult spell. It offers strong profitability and growth prospects. I was combining my five with the mining giant Rio Tintowhich looks like a cheap trade is 9.3 times earnings and has a high yield of 6.48%.

Share prices tend to fluctuate over time, but history shows that they outperform all competing asset classes over time. That's why I base my retirement plans around them.