Water leak under kitchen sink

I have just noticed a serious water leak from the connector to the cold tap under the sink in kitchen.  When pump is put on it gushes out of the sides of the push on type connector.  I have tried pushing both ends of the connector but still leaks.  With mobility issues how can I get the connector off and replace.  Regards  D. Hatton

The leak may be from the braided pipe, not the connector. These seem very prone to perishing at the ends, with alarming results. They're called 'tails' in the plumbing trade and are readily available (check - they come in different lengths).