Moody’s today downgraded Barclays PLC (NYSE:BCS) (LON:BARC) rating  from ‘stable’ to ‘negative’ in light of the resignations of three senior officials;chief executive Bob Diamond, Chairman Marcus Agius, Chief Operating Officer Jerry del Missier.

Moody’s Corporation (NYSE:MCO) cut its outlook on Barclays’ C-/baa2 standalone bank financial strength rating (BFSR) to negative from stable. The C-/ baa2 standalone BFSR as well as the A2 long-term and Prime-1 short-term debt ratings remain unchanged.

Barclays announced Diamond’s resignation on Tuesday and just hours later his departure was followed by the company’s Chief Operating Officer Jerry del Missier. Chairman Marcus Agius also announced his intention to leave once successors are found.

All three resigned last week, after US and British agencies fined Barclays $435 million for making false submissions, on borrowing costs and manipulating London interbank offered rate (LIBOR), a benchmark rate for inter-bank borrowing.

According to Moody’s, the downgrade was necessary, reflecting the uncertainty surrounding the bank’s direction which in certainly not in the interest of stakeholders.

The rating agency told shareholders that political pressure could pressure Barclay’s to shift its business model away from investment banking, and to reform perceived failures in its business culture.

“Although this could have potentially positive implications over the longer term, the uncertainty surrounding such a change in direction is credit-negative in the short term,” Moody’s said in a statement announcing the downgrade.

Furthermore, Moody’s notes other reasons for the downgrade, including the fact that there is now a large vacancy at the highest levels of the bank:

“The bank could be challenged to replace the three senior staff and in particular find a new CEO who not only has a sufficient understanding of the investment banking business to run Barclays, but also has the credibility and ability to swiftly address the weaknesses that the LIBOR incident revealed and stakeholders’ perceptions of the investment bank.”

As a result of the scandal, the British government is thinking of separating retail banking from the riskier activities of investment banking, a move which has been strongly opposed by Barclays.

The cut – from stable to negative – comes just ahead of voting among MPs to decide on whether Parliament or a judge should stage an investigation into the Libor-fixing scandal. Further downgrades could lead to higher funding costs for the bank, which ultimately will result in higher costs for its customers on the accounts, loans or mortgages they hold.

Moody’s said that Barclays’ senior debt and standalone ratings “could experience further downward pressure if the bank proved to be unable to restore a stable management structure over the coming months.”