Legal Advice – Director Dispute

I am seeking legal advice regarding a dispute between directors which is preventing the company from operating properly, most urgently in relation to opening a new company bank account with all directors authorised.
Company background
Three directors
One director holds 75% of the shares
Two directors (myself included) collectively hold 25%
No shareholders’ agreement is in place
Primary issue – company banking The company’s existing bank account has been closed by the bank under clause 13.2 of its terms. We have been informed that correspondence was sent to the majority shareholder only.
Due to a complete breakdown in communication, the majority shareholder is refusing to engage or cooperate, which means we are currently unable to open a replacement company bank account with all directors properly authorised. This is now preventing the company from receiving income, managing funds, and operating lawfully.
Related concerns
Jointly owned HMO property (licensed for 6 rooms)
Ownership mirrors shareholding (75% / 25%)
All directors are personal guarantors on the mortgage
Rental income records appear to show only 4 tenants
No transparency regarding full rental income or confirmation that mortgage payments are being maintained
Our concerns
Exposure as personal guarantors
Risk to credit ratings
Inability to access or control company funds
Possible breach of directors’ fiduciary duties
Lack of minority protection in the absence of a shareholders’ agreement
Advice requested We would welcome your advice on:
Our rights and remedies as minority shareholders
Steps available to address director obstruction
Legal mechanisms to enable the opening of a new company bank account
Whether formal correspondence should be sent, and if so, the appropriate form and tone