Executor refusing to allow access to a copy of the will (England)

Any advice welcome. Our father passed away a month ago, and it became obvious that there was no copy of his most recent will in his paperwork. I contacted his solicitors who confirmed the had a copy (the original firm was bought by a larger concern) and we then contacted the other executor who is a family member by marriage. After the family executor met with the solicitors to discuss probate at receive a copy of the will, I have asked on several occasions regarding the contents of the will and have been refused, then drip-fed parts, and told we, as a family, don't need to see it. The issue is that the estate is not large, but there is a going-concern business which my Dad and brother operated jointly, plus 2 joint assets which were bought after the will was made. My mum is now becoming ill with worry as the business is also her home, but also it's leased rather than freehold. I know once probate is granted the will is a public document but this flat-out refusal to show us the will is stopping us grieving and causing terrible stress. Can I force him to show us a copy? Thanks