**Exhibit 12.1** I, António Horta-Osório,    certify that:         1. I have reviewed this annual report on    Form 20-F    of Abbey National plc;     2. Based on my knowledge, this report does not contain any    untrue statement of a material fact or omit to state a material    fact necessary to make the statements made, in light of the    circumstances under which such statements were made, not    misleading with respect to the period covered by this report;     3. Based on my knowledge, the financial statements, and    other financial information included in this report, fairly    present in all material respects the financial condition,    results of operations and cash flows of the company as of, and    for, the periods presented in this report;     4. The company’s other certifying officer and I are    responsible for establishing and maintaining disclosure controls    and procedures (as defined in Exchange Act    Rules 13a-15(e)    and    15d-15(e))    and internal control over financial reporting (as defined in    Exchange Act Rules    13a-15(f)    and    15d-15(f))    for the company and have:     (a) Designed such disclosure controls and procedures, or    caused such disclosure controls and procedures to be designed    under our supervision, to ensure that material information    relating to the company, including its consolidated    subsidiaries, is made known to us by others within those    entities, particularly during the period in which this report is    being prepared;     (b) Designed such internal control over financial    reporting, or caused such internal control over financial    reporting to be designed under our supervision, to provide    reasonable assurance regarding the reliability of financial    reporting and the preparation of financial statements for    external purposes in accordance with generally accepted    accounting principles;     (c) Evaluated the effectiveness of the company’s    disclosure controls and procedures and presented in this report    our conclusions about the effectiveness of the disclosure    controls and procedures, as of the end of the period covered by    this report based on such evaluation; and     (d) Disclosed in this report any change in the    company’s internal control over financial reporting that    occurred during the period covered by the report, that has    materially affected, or is reasonably likely to materially    affect, the company’s internal control over financial    reporting; and     5. The company’s other certifying officer and I have    disclosed, based on our most recent evaluation of internal    control over financial reporting, to the company’s auditors    and the audit committee of the company’s board of directors    (or persons performing the equivalent functions):     (a) All significant deficiencies and material weaknesses in    the design or operation of internal control over financial    reporting which are reasonably likely to adversely affect the    company’s ability to record, process, summarize and report    financial information; and     (b) Any fraud, whether or not material, that involves    management or other employees who have a significant role in the    company’s internal control over financial reporting.      By: /s/  António    Horta-Osório    António Horta-Osório    Chief Executive Dated: 4 March 2008