[tcolvin]

There appears to be available a definitive answer to what Chris Goss writes in his two published accounts; a) “The reason for the sudden cessation of 'tip and run' attacks has never been satisfactorily explained” (page 287 in 'LW Fighter-Bombers over Britain'), and
b) “inexplicably 'tip and run' attacks had finished. After 15 months, the campaign was over.” (page 24 in 'Schlachtflieger. LW Ground-Attack Units 1937-1945').

The answer is given by JC Masterman (pages 191, and 97/98 in “The Double Cross System. 1939-1945”) where he discussed agent CARELESS.
Agent: CARELESS.
Method of communication: s/w (secret ink)
Main tasks: RAF information, especially delivery of American aircraft. Also production of AA defences.
Date of starting work: July 1941.
Date of finishing work: January 1943.
Reason for conclusion of case: Refused to continue to work.
Remarks: His personal conduct and the consequent impossibility of controlling him except in prison spoiled a promising case.
“CARELESS was a Polish airman who was shot down by the Germans in 1939, subsequently lived in France, found his way to Spain, and there got in touch with the Germans. His case was complicated by the fact that he was denounced by three Polish companions after his voyage to this country in July 1941, but he succeeded in establishing himself and communicated with the Germans by secret writing. CARELESS was considered to be difficult and temperamental; but he promised well as a double agent. His questionnaire was concerned mainly with the supply of aeroplanes to England from the USA, including the methods and routes by which they were brought here. He was also asked for general information about the RAF in Britain, and in November he received a letter urging him to get into an armament factory and obtain production figures and so forth there. His traffic, however, was particularly concerned with AA defences, since he was notionally placed by us in the balloon barrage. He had considerable success in building up the AA defences in general and the balloon barrage in particular, and was thus able to instil into the Germans a wholesome fear of the strength of our passive defences”.

NB; the dates fit, the subject fits, and Masterman makes big claims for the success of CARELESS.
It is clear that when Tip-and-run became an embarrassment for the government and the RAF, with questions in the House of Commons, Churchill would decide to use every means to counter it and would refer the matter to the Twenty Committee.

Masterman's original prefaratory note was redacted and first published in the 1995 edition in the introduction by Nigel West.
In his preferatory note, Masterman listed the M.I.5 records that should be consulted if more detail is required.
More detail is now required.
There is no one more qualified to ask to see these records and to assess their content in this case than Chris Goss.
The M.I.5 records contain, in Masterman's words,
- The complete traffic of the agents, which is of paramount importance
- The personal files of the individual agents
- The minutes of the XX Committee from January 1941 to May 1945.
- A series of subject files dealing with policy in regard to special agents and their traffic
- A series of files containing weekly summaries of current cases.
What follows from all of this, of course, is the opening up of the whole subject of the Catford bombing.
Other agents were in touch with the Germans by wireless during this period reporting on RAF and defence matters – DRAGONFLY, FATHER (reception only), FREAK, GARBO, JEFF, MUTT, TATE, TREASURE, TRICYCLE and ZIGZAG.
The M.I.5 records for these agents might reveal that the Germans were told in advance about the balloon barrage being down on January 20, 1943 for radar calibration (an obvious cover-story).
This would have been done in order to raise confidence further in the bona fides of the XX agent who supplied the information, who was probably DRAGONFLY.
This paid off when the daylight hit-and-run raids were finally abandoned due to XX misinformation that was accepted by the Luftwaffe Command, and the jabos switched to night operations.
The XX information from DRAGONFLY would have been received through Kliemann of I. Luft Paris, who controlled TREASURE and DRAGONFLY - see Masterman page 143.
The Jabo pilots, on the other hand, were incredulous about the switch to night operations – see Chris Goss page 23 – but no one listened to them.
For the RAF it was win-win; either they would tempt the GAF to raid London so they could be ambushed and destroyed by the Typhoons, and/or the agent would build up such a reputation with the Germans that they would believe anything, including misinformation that what they were doing was having no effect.
Which is what actually happened since the RAF made a pig's ear of the ambush.
Note that one of the pilots in the newsreels, referred to by Austin, said he was late getting airborne because he was somewhere else when the scramble came.
But everyone should be aware that the existence of the Double Cross System was known only to a tiny number of people; its great success was persuading the Germans to keep seven divisions in the Pas de Calais during the Normandy invasion to counter the mythical FUSAG (First US Army Group).
Certainly RAF pilots would never have guessed about XX in a million years.
It has not been fingered until now in the tip and run cancellation, as far as I know.
Finally the M.I.5 personal files might explain why CARELESS refused to continue to work after January 1943; perhaps he felt responsible for the carnage in Sandhurst School, Catford.
It is possible Polish readers of this thread may know the identity of agent CARELESS; it would be interesting to know it and his fate.
Nigel West maintained the anonymity of CARELESS while naming almost everyone else, including DRAGONFLY who was a German born in England called Mr George.
CARELESS must be dead by now.

Tony