Companies House protect the use of ENGLAND, ENGLISH, WALES, WELSH, SCOTLAND, SCOTTISH, NORTHERN IRELAND or NORTHERN IRISH when used in a company name.
The main requirement to to include a country in a company name is that the registered office must be located in that country. For example, ABC CONSULTING WALES LTD would need to have a Welsh registered office. When the word is included in your company name, but is not at the start, then you simply need to use the correct registered office address.
Should your preferred company name imply a connection to the UK government, it may be rejected. If Companies House believe people could misinterpret the company to be a government organisation they will not allow the name to be registered. You would need to obtain written approval form the relevant government department confirming they agree to the registration of your company name. This document can be a physical letter or an email from the government department.