The simple answer is, no. By law, you cannot stop your employees from discussing salaries. The Equality Act 2010 makes it unlawful for employers to prevent or restrict employees from having discussions around their pay. The Act also addresses pay secrecy clauses in employment contracts, and these are now unenforceable.
However, while you cannot prohibit employees from discussing their pay internally, you can ask them not to discuss their salaries, and in particular to keep pay rates confidential outside of the company, and to not discuss them with competitors or external parties.
When it comes to employment law, there are no silly questions!
