S&P/ASX 200 Index (ASX: XJO) bank shares have rallied over the last few months. After this impressive rally, it's worth asking if this sector is good value today or whether it has risen too far.

Let's look at how the biggest banks have performed.

In the last six months, the Commonwealth Bank of Australia (ASX: CBA) share price has gained 17%, shares in Westpac Banking Corp (ASX: WBC) are up 24%, the National Australia Bank Ltd (ASX: NAB) share price has lifted 18% and the ANZ Group Holdings Ltd (ASX: ANZ) shares are 13% higher.

The chart below shows the performance of the CBA share price over the past 12 months.

According to the Australian Financial Review, the broker Citi suggests that all four major ASX 200 bank shares are sells. Citi downgraded its ratings on Westpac and ANZ — joining the negative view on CBA and NAB.

The broker said CBA shares were too expensive amid political attacks on profits whereby lenders would be obligated to pass on any Reserve Bank of Australia (RBA) rate cuts. This may negatively impact profitability.

Citi analyst Brendan Sproules had this to say:

The reality is that cuts are unlikely to firm up earnings to justify the share price run. Falling cash rates bring additional challenges such as headwinds to low-rate deposits, political difficulties with repricing loans, and the deterioration in asset quality that rate cuts imply.

One of the points offered by the bulls in an easing cycle is that it will provide scope for the banks to reprice mortgages

We think that politically, the banks will find it difficult to reprice. Politically, cost-of-living pressures are front of mind.

Other sectors, such as the supermarkets, are facing immense pressure … and after recovering from the 2018 royal commission, the banks will be unlikely to want to cede some of their recovered goodwill and social licence.

Looking at the independent forecasts on Commsec, the CBA share price is valued at 20x FY24's estimated earnings, the Westpac share price is valued at 14x FY24's estimated earnings, the NAB share price is valued at 15x FY24's estimated earnings and the ANZ share price is valued at 13x FY24's estimated earnings.

Each of these price/earnings (P/E) ratio multiples are higher than they have been in the recent past. It's possible there may be a time in the future when the P/E ratio is cheaper than it is today. I'd avoid them for now and look at other ASX dividend shares.