Buying UK shares in a Stocks and Shares ISA could prove to be a sound means of improving your retirement prospects.Certainly, there’s an ongoing risk from a second stock market crash. However, many FTSE 100 companies appear to offer sound long-term growth prospects that could translate into rising share prices.5G is here – and shares of this ‘sleeping giant’ could be a great way for you to potentially profit!According to one leading industry firm, the 5G boom could create a global industry worth US$12.3 TRILLION out of thin air…And if you click here we’ll show you something that could be key to unlocking 5G’s full potential…With that in mind, here are two British stocks that could be worth buying in a Stocks and Shares ISA today. They could deliver impressive total returns after an uncertain period that helps to bring your retirement date a step closer.A growth opportunity among UK sharesWhile the near-term prospects for UK shares such as Unilever (LSE: ULVR) may be challenging, the company’s long-term growth potential appears to be sound.Its recent updates have shown a resilient performance despite weak trading conditions. For example, its underlying sales in the first half of the year declined by just 0.1% despite weak consumer confidence in many of its key markets.The company is also making changes to its structure and reviewing its asset portfolio to strengthen its competitive position. And, with it having a wide range of brands that resonate with consumers, its potential to deliver improving profitability appears to be high.Looking ahead, Unilever is forecast to return to net profit growth next year. That comes after an expected decline in earnings this year.Its dividend yield of 3.1% isn’t among the highest in the FTSE 100. But it’s covered 1.5 times by profit, and that could deliver inflation-beating growth in the coming years.This could catalyse its share price and help it to outperform other UK shares in the long run.The right investment strategy for uncertain conditionsMorrisons (LSE: MRW) is another company that’s experienced difficult trading conditions during a challenging period for UK shares. The supermarket has been able to deliver rising sales in the past six months, while also shifting its focus towards digital opportunities.For example, in the first half of the year, its online and home delivery order capacity increased fivefold. This should help to position it for long-term growth, with many consumers likely to continue to shop online in the coming years.Morrisons has also invested in pricing and in service improvements to boost its competitive position. Despite higher short-term costs, this could lead to rising profitability in the long run that helps the company to grow its market share.The company’s shares have a dividend yield of around 4.5%. That means they seem to offer good value for money relative to other UK shares at the present time.As such, now could be the right time to buy them in a Stocks and Shares ISA. They could boost your portfolio’s prospects and help to bring your retirement date a step closer. I would like to receive emails from you about product information and offers from The Fool and its business partners. Each of these emails will provide a link to unsubscribe from future emails. More information about how The Fool collects, stores, and handles personal data is available in its Privacy Statement. Stock market crash: 2 UK shares I’d buy in a Stocks and Shares ISA today to retire early “This Stock Could Be Like Buying Amazon in 1997” I’m sure you’ll agree that’s quite the statement from Motley Fool Co-Founder Tom Gardner.But since our US analyst team first recommended shares in this unique tech stock back in 2016, the value has soared.What’s more, we firmly believe there’s still plenty of upside in its future. In fact, even throughout the current coronavirus crisis, its performance has been beating Wall St expectations.And right now, we’re giving you a chance to discover exactly what has got our analysts all fired up about this niche industry phenomenon, in our FREE special report, A Top US Share From The Motley Fool. Enter Your Email Address See all posts by Peter Stephens Renowned stock-picker Mark Rogers and his analyst team at The Motley Fool UK have named 6 shares that they believe UK investors should consider buying NOW.So if you’re looking for more stock ideas to try and best position your portfolio today, then it might be a good day for you. Because we’re offering a full 33% off your first year of membership to our flagship share-tipping service, backed by our ‘no quibbles’ 30-day subscription fee refund guarantee. Peter Stephens | Thursday, 1st October, 2020 | More on: MRW ULVR Image source: Getty Images Click here to claim your copy now — and we’ll tell you the name of this Top US Share… free of charge! Our 6 ‘Best Buys Now’ Shares Peter Stephens owns shares of Morrisons and Unilever. The Motley Fool UK has recommended Unilever. Views expressed on the companies mentioned in this article are those of the writer and therefore may differ from the official recommendations we make in our subscription services such as Share Advisor, Hidden Winners and Pro. Here at The Motley Fool we believe that considering a diverse range of insights makes us better investors. Simply click below to discover how you can take advantage of this.