It is against the law to get married again if your previous marriage has not been legally annulled. You cannot get married again without first getting a divorce to end the first marriage. If you would like to remarry, your previous marriage has to be legally dissolved by way of a Final Order or Decree Absolute (which it used to be known as before 6th April 2022). This confirms that a divorce is officially finalised. To apply for a Final Order, you have to wait a minimum of six weeks and one day (or 43 days) from the date the Conditional Order or Decree Nisi (what it used to be called) is issued.
In saying this, some religions have different rules on whether someone can marry again in a religious ceremony. If you would like to remarry in a religious ceremony you will have to check with an office holder in the relevant religion to find out if you can. However, doing so is at the discretion of the official conducting the ceremony.